Medical device for removing an implanted object

ABSTRACT

Methods and devices for separating an implanted object, such as a pacemaker lead, from tissue surrounding such object in a patient&#39;s vasculature system. Specifically, the surgical device includes a handle, an elongate sheath and a circular cutting blade that extends from the distal end of the sheath upon actuating the handle. The circular cutting blade is configured to engage the tissue surrounding an implanted lead and cut such tissue in a coring fashion as the surgical device translates along the length of the lead, thereby allowing the lead, as well as any tissue remaining attached to the lead, to enter the device&#39;s elongate shaft. The surgical device has a barrel cam cylinder in the handle assembly that imparts rotation of the blade and a separate cam mechanism in the tip of outer sheath assembly that imparts and controls the extension and retraction of the blade. The barrel cam cylinder and cam mechanism cooperate to cause the blade to rotate in a first direction and extend from and retract in the outer sheath due to a first actuation of the handle and to rotate in a second direction and extend and retract in the outer sheath due to a second actuation of the handle.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-In-Part of International ApplicationNo. PCT/US2014/026496, filed Mar. 13, 2014 and entitled SURGICALINSTRUMENT FOR REMOVING AN IMPLANTED OBJECT, which claims the benefit ofand priority to, under 35 U.S.C. §119(e), U.S. Provisional ApplicationSer. No. 61/793,597, filed Mar. 15, 2013, entitled SURGICAL INSTRUMENTFOR REMOVING AN IMPLANTED OBJECT. The present application also claimsthe benefit of and priority to, under 35 U.S.C. §119(e), U.S.Provisional Application Ser. No. 61/947,377, filed Mar. 3, 2014,entitled MEDICAL DEVICE FOR REMOVING AN IMPLANTED OBJECT, U.S.Provisional Application Ser. No. 62/058,790, filed Oct. 2, 2014,entitled MEDICAL DEVICE FOR REMOVING AN IMPLANTED OBJECT, and U.S.Provisional Application Ser. No. 62/113,865, filed Feb. 9, 2015,entitled MEDICAL DEVICE FOR REMOVING AN IMPLANTED OBJECT. The aboveapplications are hereby incorporated by reference in their entiretiesfor all that they teach and for all purposes.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to devices, methods and systemsfor separating tissue in a patient's vascular system, and morespecifically, to devices for separating tissue attached to implantedobjects, such as leads, in a patient's vascular system and removing suchobjects.

BACKGROUND

Surgically implanted cardiac pacing systems, such as pacemakers anddefibrillators, play an important role in the treatment of heartdisease. In the 50 years since the first pacemaker was implanted,technology has improved dramatically, and these systems have saved orimproved the quality of countless lives. Pacemakers treat slow heartrhythms by increasing the heart rate or by coordinating the heart'scontraction for some heart failure patients. Implantablecardioverter-defibrillators stop dangerous rapid heart rhythms bydelivering an electric shock.

Cardiac pacing systems typically include a timing device and a lead,which are placed inside the body of a patient. One part of the system isthe pulse generator containing electric circuits and a battery, usuallyplaced under the skin on the chest wall beneath the collarbone. Toreplace the battery, the pulse generator must be changed by a simplesurgical procedure every 5 to 10 years. Another part of the systemincludes the wires, or leads, which run between the pulse generator andthe heart. In a pacemaker, these leads allow the device to increase theheart rate by delivering small timed bursts of electric energy to makethe heart beat faster. In a defibrillator, the lead has special coils toallow the device to deliver a high-energy shock and convert potentiallydangerous rapid rhythms (ventricular tachycardia or fibrillation) backto a normal rhythm. Additionally, the leads may transmit informationabout the heart's electrical activity to the pacemaker.

For both of these functions, leads must be in contact with heart tissue.Most leads pass through a vein under the collarbone that connects to theright side of the heart (right atrium and right ventricle). In somecases, a lead is inserted through a vein and guided into a heart chamberwhere it is attached with the heart. In other instances, a lead isattached to the outside of the heart. To remain attached to the heartmuscle, most leads have a fixation mechanism, such as a small screwand/or hooks at the end.

Within a relatively short time after a lead is implanted into the body,the body's natural healing process forms scar tissue along the lead andpossibly at its tip, thereby fastening it even more securely in thepatient's body. Leads usually last longer than device batteries, soleads are simply reconnected to each new pulse generator (battery) atthe time of replacement. Although leads are designed to be implantedpermanently in the body, occasionally these leads must be removed, orextracted. Leads may be removed from patients for numerous reasons,including but not limited to, infections, lead age, and leadmalfunction.

Removal or extraction of the lead may be difficult. As mentioned above,the body's natural healing process forms scar tissue over and along thelead, and possibly at its tip, thereby encasing at least a portion ofthe lead and fastening it even more securely in the patient's body. Inaddition, the lead and/or tissue may become attached to the vasculaturewall. Both results may, therefore, increase the difficulty of removingthe leads from the patient's vasculature.

A variety of tools have been developed to make lead extraction safer andmore successful. Current lead extraction techniques include mechanicaltraction, mechanical devices, and laser devices. Mechanical traction maybe accomplished by inserting a locking stylet into the hollow portion ofthe lead and then pulling the lead to remove it. An example of such alead locking device is described and illustrated in U.S. Pat. No.6,167,315 to Coe et al., which is hereby incorporated herein byreference in its entirety for all that it teaches and for all purposes.

A mechanical device to extract leads may include one or more a flexibletubes called a sheath that passes over the lead and/or the surroundingtissue. One of the sheaths may include a tip having a dilator, aseparator and/or a cutting blade, such that upon advancement, the tip(and possibly the sheath cooperate to) dilates, separates and/or cuts toseparate the scar tissue from other scar tissue including the scartissue surrounding the lead. In some cases, the tip (and sheath) mayalso separate the tissue itself from the lead. Once the lead isseparated from the surrounding tissue and/or the surrounding tissue isseparated from the remaining scar tissue, the lead may be inserted intoa hollow lumen of the sheath for removal and/or be removed from thepatient's vasculature using some other mechanical devices, such as themechanical fraction device previously described in United States PatentPublication No. 2008/0154293 to Taylor, which is hereby incorporatedherein by reference in its entirety for all that it teaches and for allpurposes.

Some lead extraction devices include mechanical sheaths that havetrigger mechanisms for extending the blade from the distal end of thesheath. An example of such devices and method used to extract leads isdescribed and illustrated in U.S. Pat. No. 5,651,781 to Grace, which ishereby incorporated herein by reference in its entirety for all that itteaches and for all purposes. Another example of these device that has atrigger mechanism for extending the blade from the distal end of thesheath is described and illustrated in United States Patent PublicationNo. 2014/0277037 having application Ser. No. 13/834,405 filed Mar. 14,2013, which is hereby incorporated herein by reference in its entiretyfor all that it teaches and for all purposes.

Controlling the amount of extension and refraction of the blade within apatient's vasculature may be critical, particularly when the sheath andblade negotiate tortuous paths that exist in certain vascular orphysiological environments and/or when the blade is attempting to cutand/or separate tough surrounding tissue. Furthermore, in certain cases,using such mechanical devices for lead removal may require moremeticulous control, such as when the leads are located in, and/orattached to a structurally-weak portion of the vasculature. Forinstance, typical leads in a human may pass through the innominate vein,past the superior vena cava (“SVC”), and into the right atrium of theheart. Tissue growth occurring along the SVC and other locations alongthe innominate vein may increase the risk and difficulty in extractingthe leads from such locations, particularly when the vein(s)′ walls arethin and the surrounding tissue is notably fibrous.

SUMMARY

Accordingly, there is a need for a device, method and/or system such asa surgical device that has the capability to precisely control theextension, retraction and rotation of a blade from within an outersheath. For example, it may be desirable for the blade to rotate in onedirection as the blade initially extends from and retracts within theouter sheath, then rotate in an opposite direction upon subsequentextension and retraction during the same actuation of the surgicaldevice. The present disclosure discusses a surgical device that has abarrel cam cylinder in the handle assembly that imparts rotation of theblade and a separate cam mechanism in the tip of outer sheath assemblythat imparts and controls the extension and retraction of the blade. Thebarrel cam cylinder and cam mechanism cooperate to cause the blade torotate in one direction as it initially extends from and retracts in theouter sheath and to rotate in a second direction as it extends andretracts a second time. For each actuation of the handle, the bladerotates in one direction as it initially extends from and retracts intoouter sheath and subsequently rotates in a second direction as itextends and retracts a second time. Alternating the direction ofrotation in conjunction with the extension and retraction of the bladeduring rotation creates a slicing action in one direction for eachextension and retraction of the blade, thereby minimizing the potentialfor the blade to become jammed in the surrounding tissue.

A device in accordance with this disclosure for removing an implantedobject from a body vessel, may comprise a sheath assembly comprising anouter sheath assembly and an inner sheath assembly, and a pin, the outersheath assembly comprising an outer sheath and an outer band, the outerband coupled to the pin, the inner sheath assembly comprising an innersheath and a tip, wherein the tip has a cutting surface, the innersheath comprising a proximal end and a distal end, wherein the distalend of the inner sheath is coupled to the tip, the tip comprising a camslot for receipt of and cooperation with the pin, and a handle assemblycomprising a trigger and a barrel cam cylinder, the trigger comprising atrigger pin, the barrel cam cylinder comprising a barrel cam cylinderslot for receipt and cooperation with the trigger pin, wherein theproximal end of the inner sheath is coupled to the barrel cam cylindersuch that upon the trigger pin moving proximally in a longitudinaldirection, the barrel cam cylinder rotates in both a clockwise directionand a counter clockwise direction, thereby causing the tip to rotate inboth the clockwise direction and the counter clockwise direction whilethe tip moves longitudinally.

A device in accordance with this disclosure for removing an implantedobject from a body vessel, may alternatively comprise a sheath assemblycomprising an outer sheath assembly and an inner sheath assembly, and apin, wherein the outer sheath assembly and the inner sheath assemblyeach comprise a proximal end and a distal end, wherein the distal end ofthe outer sheath assembly is coupled to the distal end of the innersheath assembly by the pin, the inner sheath assembly comprising aninner sheath and a tip at its distal end, wherein the tip has a cuttingsurface, the tip comprising a slot for receipt of and cooperation withthe pin, and a handle assembly comprising a trigger and a barrel camcylinder, the trigger comprising a trigger pin, the barrel cam cylindercomprising a barrel cam cylinder slot for receipt and cooperation withthe trigger pin, wherein the proximal end of the inner sheath is coupledto the barrel cam cylinder by the trigger pin such that upon the triggerpin moving proximally in a longitudinal direction, the barrel camcylinder rotates in a first direction and a second direction, whereinthe first direction is different than the second direction, wherein thetip moves longitudinally while the barrel cam cylinder rotates in thefirst direction, and wherein the tip moves longitudinally while thebarrel cam cylinder rotates in the second direction.

There is a need for a device, method and/or system such as a surgicaldevice that has the capability to precisely control the extension,retraction and rotation of a blade from within an outer sheath. Forexample, it may be desirable for the blade to rotate in one direction asthe blade initially extends from and retracts within the outer sheath,then rotate in an opposite direction upon subsequent extension andretraction during the same actuation of the surgical device. The presentdisclosure discusses a surgical device that has a barrel cam cylinder inthe handle assembly that imparts rotation of the blade and a separatecam mechanism in the tip of outer sheath assembly that imparts andcontrols the extension and retraction of the blade. The barrel camcylinder and cam mechanism cooperate such that (1) upon a firstactuation of the device, the barrel cam cylinder rotates in a firstdirection, thereby causing the blade to rotate in the first directionwhile the blade extends and retracts, and (2) upon a second actuation ofthe device, the barrel cam cylinder rotates in a second direction,thereby causing the blade to rotate in the second direction while theblade extends and retracts. Alternating the direction of rotation inconjunction with the extension and retraction of the blade duringrotation creates a slicing action that minimizes the potential for theblade to become jammed in the surrounding tissue.

A device in accordance with this disclosure for removing an implantedobject from a body vessel, may comprise a sheath assembly comprising anouter sheath assembly and an inner sheath assembly, and a pin, the outersheath assembly comprising an outer sheath and an outer band, the outerband coupled to the pin, the inner sheath assembly comprising an innersheath and a tip, wherein the tip has a cutting surface, the innersheath comprising a proximal end and a distal end, wherein the distalend of the inner sheath is coupled to the tip, the tip comprising a camslot for receipt of and cooperation with the pin, and a handle assemblycomprising a trigger and a barrel cam cylinder, the trigger comprising atrigger pin, the barrel cam cylinder comprising a barrel cam cylinderslot for receipt and cooperation with the trigger pin, wherein theproximal end of the inner sheath is coupled to the barrel cam cylindersuch that (1) upon a first actuation of the trigger to proximally movethe trigger pin in a longitudinal direction, the barrel cam cylinderrotates in a first direction, thereby causing the tip to rotate in thefirst direction while the tip moves longitudinally; and (2) upon asecond actuation of the trigger to proximally move the trigger pin inthe longitudinal direction, the barrel cam cylinder rotates in a seconddirection, thereby causing the tip to rotate in the second directionwhile the tip moves longitudinally.

A device in accordance with this disclosure for removing an implantedobject from a body vessel, may comprise a sheath comprising a proximalend and a distal end, a tip coupled to the distal end of the sheath,wherein the tip has a cutting surface, a handle assembly rotatablycarrying the sheath, the handle assembly comprising a trigger comprisinga trigger pin; and a barrel cam assembly comprising a barrel camcylinder comprising a barrel cam cylinder slot for receipt andcooperation with the trigger pin, the barrel cam cylinder slotcomprising a first slot portion and a second slot portion; a followerguide rotatably carried by the barrel cam cylinder; wherein upon a firstactuation of the trigger to proximally move the trigger pin in alongitudinal direction, the follower guide urges the trigger pin totraverse the first slot portion, thereby causing the barrel cam cylinderand the tip to rotate in the first direction; and wherein upon a secondactuation of the trigger to proximally move the trigger pin in alongitudinal direction, the follower guide urges the trigger pin totraverse the second slot portion, thereby causing the barrel camcylinder and the tip to rotate in the second direction.

The phrases “at least one”, “one or more”, and “and/or” are open-endedexpressions that are both conjunctive and disjunctive in operation. Forexample, each of the expressions “at least one of A, B and C”, “at leastone of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B,or C” and “A, B, and/or C” means A alone, B alone, C alone, A and Btogether, A and C together, B and C together, or A, B and C together.When each one of A, B, and C in the above expressions refers to anelement, such as X, Y, and Z, or class of elements, such as X₁-X_(n),Y₁-Y_(m), and Z₁-Z_(o), the phrase is intended to refer to a singleelement selected from X, Y, and Z, a combination of elements selectedfrom the same class (e.g., X₁ and X₂) as well as a combination ofelements selected from two or more classes (e.g., Y₁ and Z_(o)).

The term “a” or “an” entity refers to one or more of that entity. Assuch, the terms “a” (or “an”), “one or more” and “at least one” may beused interchangeably herein. It is also to be noted that the terms“comprising”, “including”, and “having” may be used interchangeably.

A “barrel cam cylinder”, which is sometimes referred to as a“cylindrical cam”, typically includes a groove (slot or channel) cutinto the surface of a cylinder, and a follower, such as a pin, whichrides in the groove. A barrel cam cylinder is generally used to convertrotational motion to linear motion parallel to the rotational axis ofthe cylinder or to convert linear motion, parallel to the axis of thecylinder, to rotational motion. For the purposes of this disclosure,unless otherwise specified, the barrel cam cylinder may refer to thecylinder and the follower.

A “lead” is a conductive structure, typically an electrically insulatedcoiled wire. The electrically conductive material may be any conductivematerial, with metals and intermetallic alloys common. The outer sheathof insulated material is biocompatible and bio stable (e.g.,non-dissolving in the body) and generally includes organic materialssuch as polyurethane and polyimide. Lead types include, by way ofnon-limiting example, epicardial and endocardial leads. Leads arecommonly implanted into a body percutaneously or surgically.

The term “means” as used herein shall be given its broadest possibleinterpretation in accordance with 35 U.S.C. Section 112(f). Accordingly,a claim incorporating the term “means” shall cover all structures,materials, or acts set forth herein, and all of the equivalents thereof.Further, the structures, materials or acts and the equivalents thereofshall include all those described in the summary of the invention, briefdescription of the drawings, detailed description, abstract, and claimsthemselves.

A “serration” or “serrated edge” or “serrated blade” or othervariations, as used herein, shall mean the configuration of a cuttingsurface having a notched edge or saw-like teeth. The notched edgescreate a plurality of smaller points that contact (and therefore lesscontact area with) the material being cut in comparison to an un-notchedblade. Additionally, the pressure applied by each serrated point ofcontact is relatively greater and the points of contact are at a sharperangle to the material being cut. One example of a serrated blade mayinclude one notch adjacent to and abutting another notch such that thereis very little, if any, blade between such notches, thereby creatingpoints of contact. There are multiple variations and/or features ofserrations. For example, one type of serrated feature is referred to asa “crown.” As used herein, a serrated blade, or other variation, in theshape of a “crown,” shall mean a blade comprising a plurality of notchesand adjacent un-notched areas such that the combination of notched andun-notched areas resembles a crown for a royal member (e.g., king,queen, etc.), particularly when the blade is circular. A further type of“crown” includes a “hook crown.” As used herein, a serrated blade, orother variation, in the shape of a “hook crown,” shall mean a bladecomprising of a plurality of notches and adjacent un-notched areas,wherein the length of the un-notched areas ascend to the next adjacentpoint at an angle to increase the slicing action in one rotary directionand the notches are created at an angle to create a hook feature at thepoints to promote engagement with the tissue at the hook-shaped point.

A “surgical implant” or “implanted object” is a medical devicemanufactured to replace a missing biological structure, support,stimulate, or treat a damaged biological structure, or enhance,stimulate, or treat an existing biological structure. Medical implantsare man-made devices, in contrast to a transplant, which is atransplanted biomedical tissue. In some cases implants containelectronics, including, without limitation, artificial pacemaker,defibrillator, electrodes, and cochlear implants. Some implants arebioactive, including, without limitation, subcutaneous drug deliverydevices in the form of implantable pills or drug-eluting stents.

“Vasculature” or “vascular system” is any part of the circulatorysystem, which includes the heart, blood, and blood vessels such asarteries, veins and capillaries.

It should be understood that every maximum numerical limitation giventhroughout this disclosure is deemed to include each and every lowernumerical limitation as an alternative, as if such lower numericallimitations were expressly written herein. Every minimum numericallimitation given throughout this disclosure is deemed to include eachand every higher numerical limitation as an alternative, as if suchhigher numerical limitations were expressly written herein. Everynumerical range given throughout this disclosure is deemed to includeeach and every narrower numerical range that falls within such broadernumerical range, as if such narrower numerical ranges were all expresslywritten herein.

The preceding is a simplified summary of the disclosure to provide anunderstanding of some aspects of the disclosure. This summary is neitheran extensive nor exhaustive overview of the disclosure and its variousaspects, embodiments, and configurations. It is intended neither toidentify key or critical elements of the disclosure nor to delineate thescope of the disclosure but to present selected concepts of thedisclosure in a simplified form as an introduction to the more detaileddescription presented below. As will be appreciated, other aspects,embodiments, and configurations of the disclosure are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of thespecification to illustrate several examples of the present disclosure.These drawings, together with the description, explain the principles ofthe disclosure. The drawings simply illustrate preferred and alternativeexamples of how the disclosure may be made and used and are not to beconstrued as limiting the disclosure to only the illustrated anddescribed examples. Further features and advantages will become apparentfrom the following, more detailed, description of the various aspects,embodiments, and configurations of the disclosure, as illustrated by thedrawings referenced below.

FIG. 1 is a perspective view of a human having a pacemaker lead locatedin the venous system and a terminating electrode anchored to theventricular heart chamber, with an embodiment of a surgical device beingshown inserted into the body and partly advanced over the lead;

FIG. 2 is an elevation view of an embodiment of a surgical device;

FIG. 3 is a cross-sectional view of a sheath assembly within a bloodvessel with an extendable and rotatable blade for removing a leadaccording to an embodiment of the disclosure;

FIG. 4A is an internal view of an embodiment of a handle assembly of thesurgical device illustrated in FIG. 2;

FIG. 4B is a perspective view of an embodiment of a trigger for thehandle assembly illustrated in FIG. 4A;

FIG. 4C is an elevation view of an embodiment of the barrel cam cylinderfor the handle assembly illustrated in FIG. 4A;

FIG. 4D is a cross-sectional view of an embodiment of the barrel camcylinder illustrated in FIG. 4C;

FIG. 4E is an end view of an embodiment of the barrel cam cylinderillustrated in FIG. 4C;

FIG. 4F is an enlarged perspective view of an embodiment of a spool forthe handle assembly illustrated in FIG. 4A;

FIG. 5A is an elevation view of the barrel cam cylinder illustrated inFIG. 4C in its home position;

FIG. 5B is an elevation view of the barrel cam cylinder illustrated inFIG. 4C upon being rotated to about 136.5 degrees in clockwise directionand/or counter-clockwise direction;

FIG. 5C is an elevation view of the barrel cam cylinder illustrated inFIG. 4C upon being rotated to about 273.1 degrees in clockwisedirection;

FIG. 5D is an elevation view of the barrel cam cylinder illustrated inFIG. 4C upon being rotated to 307.6 degrees in a counter-clockwisedirection and toward its home position;

FIG. 5E is an end view of the barrel cam cylinder illustrated in FIG. 4Eincluding an indication of the amount of angular rotation for the camcutter at each of the barrel cam cylinder positions illustrated in FIGS.5A, 5B, 5C and 5D;

FIG. 6 is an elevation view of an embodiment of the sheath assembly;

FIG. 6A is a break-away, elevation view of an embodiment of the distalend of the sheath assembly illustrated in FIG. 6;

FIG. 6B is a break-away, elevation view of an embodiment of the proximalend of the sheath assembly illustrated in FIG. 6;

FIG. 7A is an elevation view of an embodiment of the outer sheathassembly;

FIG. 7B is an elevation view of an embodiment of the inner sheathassembly;

FIG. 8 is a cross-sectional view of an embodiment of the sheath assemblyillustrated in FIG. 6;

FIG. 8A is an enlarged cross-sectional view of the distal end of theinner sheath assembly located within the outer sheath assemblyillustrated in FIG. 8, wherein the blade is retracted and located withinthe outer sheath assembly;

FIG. 8A′ is an enlarged cross-sectional view of the distal end of theinner sheath assembly located within the outer sheath assemblyillustrated in FIG. 8, wherein the blade is extended and located outsidethe outer sheath assembly;

FIG. 8B is a distal end view of the inner sheath assembly located withinthe outer sheath assembly illustrated in FIG. 8;

FIG. 8C is an enlarged cross-sectional view of the inner key of theinner sheath assembly located within the outer key of the outer sheathassembly illustrated in FIG. 8;

FIG. 9A is a perspective view of an outer band member according to anembodiment of the disclosure;

FIG. 9B is an end view of the outer band member illustrated in FIG. 9A;

FIG. 9C is cross-sectional view of the outer band member illustrated inFIG. 9A taken along line 9C-9C of FIG. 9B;

FIG. 10A is a perspective view of a cutting tip according to anembodiment of the disclosure;

FIG. 10B is side view of the cutting tip illustrated in FIG. 10A;

FIG. 10C is end view of the cutting tip member illustrated in FIG. 10A;

FIG. 10D is cross-sectional view of the cutting tip illustrated in FIG.10A taken along line 10D-10D in FIG. 10C;

FIG. 11 is an illustration of the cam slot profile of the cutting tipand the cam slot of the barrel cam cylinder depicting the longitudinalposition of the cutting tip in combination with the longitudinalposition of the trigger for a particular amount of angular rotation byboth the cutting tip and the barrel cam cylinder;

FIG. 12 is a perspective view of a human having a pacemaker lead locatedin the venous system and a terminating electrode anchored to theventricular heart chamber, with an embodiment of a surgical device beingshown inserted into the body and partly advanced over the lead;

FIG. 13 is an elevation view of an embodiment of a surgical device;

FIG. 14 is a cross-sectional view of a sheath assembly within a bloodvessel with an extendable and rotatable blade for removing a leadaccording to an embodiment of the disclosure;

FIG. 15A is an internal view of an embodiment of a handle assembly ofthe surgical device illustrated in FIG. 13;

FIG. 15B is a perspective view of an embodiment of a trigger for thehandle assembly illustrated in FIG. 15A;

FIG. 15C is an elevation view of an embodiment of the barrel camassembly for the handle assembly illustrated in FIG. 15A;

FIG. 15D is an elevation view of a barrel cam cylinder of the barrel camassembly illustrated in FIG. 15C;

FIG. 15E is an illustration of the cam slot profile of the cam slot ofthe barrel cam cylinder illustrated in FIG. 15D;

FIG. 15F is a longitudinal-sectional view of the barrel cam cylinderillustrated in FIG. 15D;

FIG. 15G is a cross-sectional view of the barrel cam cylinderillustrated in FIG. 15D;

FIG. 15H is an elevation view of a follower guide of the barrel camassembly illustrated in FIG. 15C

FIG. 15I is an illustration of the aperture profile of the followerguide illustrated in FIG. 15H;

FIG. 15J is an end view of the barrel cam assembly of FIG. 15Cillustrating a relative rotation-inhibiting mechanism in a firstrelative rotation-inhibiting position;

FIG. 15K is an end view of the barrel cam assembly of FIG. 15Cillustrating the relative rotation-inhibiting mechanism in a secondrelative rotation-inhibiting position;

FIG. 15L is an enlarged perspective view of an embodiment of a springassembly for the handle assembly illustrated in FIG. 15A;

FIG. 16 is an elevation view of an embodiment of the sheath assembly;

FIG. 16A is a break-away, elevation view of an embodiment of the distalend of the sheath assembly illustrated in FIG. 16;

FIG. 16B is a break-away, elevation view of an embodiment of theproximal end of the sheath assembly illustrated in FIG. 16;

FIG. 17A is an elevation view of an embodiment of the outer sheathassembly;

FIG. 17B is an elevation view of an embodiment of the inner sheathassembly;

FIG. 18 is a cross-sectional view of an embodiment of the sheathassembly illustrated in FIG. 16;

FIG. 18A is an enlarged cross-sectional view of the distal end of theinner sheath assembly located within the outer sheath assemblyillustrated in FIG. 18, wherein the blade is retracted and locatedwithin the outer sheath assembly;

FIG. 18A′ is an enlarged cross-sectional view of the distal end of theinner sheath assembly located within the outer sheath assemblyillustrated in FIG. 18, wherein the blade is extended and locatedoutside the outer sheath assembly;

FIG. 18B is a distal end view of the inner sheath assembly locatedwithin the outer sheath assembly illustrated in FIG. 18;

FIG. 18C is an enlarged cross-sectional view of the inner key of theinner sheath assembly located within the outer key of the outer sheathassembly illustrated in FIG. 18;

FIG. 19A is a perspective view of an outer band member according to anembodiment of the disclosure;

FIG. 19B is an end view of the outer band member illustrated in FIG.19A;

FIG. 19C is cross-sectional view of the outer band member illustrated inFIG. 19A taken along line 19C-19C of FIG. 19B;

FIG. 20A is a perspective view of a cutting tip according to anembodiment of the disclosure;

FIG. 20B is side view of the cutting tip illustrated in FIG. 20A;

FIG. 20C is end view of the cutting tip member illustrated in FIG. 20A;

FIG. 20D is cross-sectional view of the cutting tip illustrated in FIG.20A taken along line 20D-20D in FIG. 20C;

FIG. 21 depicts two-dimensional illustrations of a profile of a cam slotof an embodiment of a cutting tip, a profile of a cam slot of anembodiment of a barrel cam cylinder, and a profile of an aperture of anembodiment of a follower guide;

FIG. 22A is an illustration of the cam slot profile of the cutting tip,the cam slot of the barrel cam cylinder, and the profile of the apertureof the follower guide depicting the longitudinal position of the cuttingtip in combination with the longitudinal position of the trigger for aparticular amount of angular rotation by both the cutting tip and thebarrel cam cylinder; the follower guide is illustrated in a firstrelative rotation-inhibiting position compared to the barrel camcylinder;

FIG. 22B is another illustration of the cam slot profile of the cuttingtip, the cam slot of the barrel cam cylinder, and the profile of theaperture of the follower guide depicting the longitudinal position ofthe cutting tip in combination with the longitudinal position of thetrigger for a particular amount of angular rotation by both the cuttingtip and the barrel cam cylinder; the follower guide is illustrated in asecond relative rotation-inhibiting position compared to the barrel camcylinder;

FIG. 22C is another illustration of the cam slot profile of the cuttingtip, the cam slot of the barrel cam cylinder, and the profile of theaperture of the follower guide depicting the longitudinal position ofthe cutting tip in combination with the longitudinal position of thetrigger for a particular amount of angular rotation by both the cuttingtip and the barrel cam cylinder; the follower guide is again illustratedin the first relative rotation-inhibiting position compared to thebarrel cam cylinder;

FIG. 23A is an elevation view of the barrel cam assembly illustrated inFIG. 15C in its first home position;

FIG. 23B is an elevation view of the barrel cam assembly illustrated inFIG. 15C upon being rotated away from its first home position;

FIG. 23C is an elevation view of the barrel cam assembly illustrated inFIG. 15C upon being rotated further away from its first home position;

FIG. 23D is an elevation view of the barrel cam assembly illustrated inFIG. 15C in its second home position;

FIG. 23E is an elevation view of the barrel cam assembly illustrated inFIG. 15C upon being rotated away from its second home position;

FIG. 23F is an elevation view of the barrel cam assembly illustrated inFIG. 15C upon being rotated further away from its second home position;

FIG. 24 is a perspective view of an embodiment of the barrel camassembly for a surgical device;

FIG. 25 is an exploded perspective view of the barrel cam assembly ofFIG. 24;

FIG. 26 is a side view of a barrel cam cylinder of the barrel camassembly of FIG. 24;

FIG. 27 is a side view of a follower guide of the barrel cam assembly ofFIG. 24;

FIG. 28 is another side view of the follower guide of FIG. 24;

FIG. 29 is a partial perspective view of an embodiment of the barrel camassembly for a surgical device;

FIG. 30 is another partial perspective view of the barrel cam assemblyof FIG. 29;

FIG. 31 is a perspective view of an embodiment of the barrel camassembly for a surgical device; a follower guide of the barrel camassembly is translucent for illustrative purposes;

FIG. 32 is a perspective view of an embodiment of the barrel camassembly for a surgical device; a follower guide of the barrel camassembly is translucent for illustrative purposes;

FIG. 33 is a perspective view of an embodiment of the barrel camassembly for a surgical device; hidden features are shown in light graylines;

FIG. 34 is another perspective view of the barrel cam assembly of FIG.33;

FIG. 35 depicts two-dimensional illustrations of a profile of a cam slotof an embodiment of a cutting tip, a profile of a cam slot of anembodiment of a barrel cam cylinder, and a profile of an aperture of anembodiment of a follower guide;

FIG. 36A is an illustration of the cam slot profile of the cutting tip,the cam slot of the barrel cam cylinder, and the profile of the apertureof the follower guide depicting the longitudinal position of the cuttingtip in combination with the longitudinal position of the trigger for aparticular amount of angular rotation by both the cutting tip and thebarrel cam cylinder; the follower guide is illustrated in a firstrelative rotation-inhibiting position compared to the barrel camcylinder;

FIG. 36B is another illustration of the cam slot profile of the cuttingtip, the cam slot of the barrel cam cylinder, and the profile of theaperture of the follower guide depicting the longitudinal position ofthe cutting tip in combination with the longitudinal position of thetrigger for a particular amount of angular rotation by both the cuttingtip and the barrel cam cylinder; the follower guide is illustrated in asecond relative rotation-inhibiting position compared to the barrel camcylinder;

FIG. 36C is another illustration of the cam slot profile of the cuttingtip, the cam slot of the barrel cam cylinder, and the profile of theaperture of the follower guide depicting the longitudinal position ofthe cutting tip in combination with the longitudinal position of thetrigger for a particular amount of angular rotation by both the cuttingtip and the barrel cam cylinder; the follower guide is again illustratedin the first relative rotation-inhibiting position compared to thebarrel cam cylinder; and

FIG. 37 depicts a two-dimensional illustration of a profile of a camslot of an embodiment of a barrel cam cylinder.

It should be understood that the drawings are not necessarily to scale.In certain instances, details that are not necessary for anunderstanding of the disclosure or that render other details difficultto perceive may have been omitted. It should be understood, of course,that the disclosure is not necessarily limited to the particularembodiments illustrated herein.

DETAILED DESCRIPTION

Before any embodiments of the disclosure are explained in detail, it isto be understood that the disclosure is not limited in its applicationto the details of construction and the arrangement of components setforth in the following description or illustrated in the followingdrawings. The disclosure is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein is for thepurpose of description and should not be regarded as limiting. The useof “including,” “comprising,” or “having” and variations thereof hereinis meant to encompass the items listed thereafter and equivalentsthereof as well as additional items.

Embodiments according to this disclosure provide a surgical device thatincludes a sheath assembly, which can be deployed safely within avascular system of a patient and separate implanted objects, such asleads, from a patient's vasculature system. FIG. 1 depicts a surgicaldevice 106 having a sheath assembly 112 inserted within an exemplarypatient 104. The sheath assembly 112 surrounds an implanted lead (notshown) running along the left innominate vein past the SVC and connectedinto, or about, the right ventricle of the heart. Upon surrounding thelead with the sheath assembly 112, the user of the surgical device 106may actuate the handle assembly 108, thereby rotating and extending acutting blade (not shown) beyond the distal end of the sheath assembly112 to dilate, separate and/or cut the tissue surrounding the leadwithin the patient's SVC.

The cutting blade may extend from and retract into the sheath multipletimes upon actuation of the handle assembly according to the profile ofthe cam slot in the cutting tip disclosed below. The cutting blade mayalso rotate in both a clockwise and counter-clockwise direction per theprofile of the cam slot in the barrel cam cylinder discussed below. Whenthe clinician releases the handle assembly, the cutting blade is ensuredto remain or return within the sheath assembly 112, thereby allowing theclinician to force and advance the distal portion of the sheath assemblyagainst additional uncut tissue. The clinician repeats the actuationstep, thereby causing the cutting blade to re-appear and extend beyondthe distal end of the sheath assembly 112 to cut the adjacent tissue.Each time actuation occurs, the proximal portion of the implanted leadand/or surrounding tissue enters further into a hollow passageway withinthe sheath assembly 112. This process is again repeated until theimplanted lead and/or surrounding tissue is completely or substantiallydilated, separated, and/or cut from the tissue attached to the SVC. Atthat time, the implanted lead may safely be removed from the patient'sSVC.

With reference to FIG. 2, an exemplary surgical device 106 is depicted.The surgical device 106 includes a handle assembly 108 and a flexiblesheath assembly 112. The flexible sheath assembly 112, which isdiscussed in more detail below, generally includes a flexible innersheath assembly (not shown) located within a flexible outer sheathassembly. It may be preferable for the outer sheath to remain stationarywhile the inner sheath is capable of moving (e.g., rotating andextending) with respect to the outer sheath. The inner sheath and outersheath can both be flexible, rigid or a combination thereof.

With reference to FIG. 4A, an exemplary handle assembly is depicted. Thehandle assembly 108 may include some or all of the following components:a handle frame 404, a trigger 408, a spring assembly 412, a strainrelief component 416, a barrel cam cylinder 420, a bushing 424 and anend cap 427. The handle frame 404 may be constructed of a singularcomponent or multiple component, such as two halves as illustrated inFIG. 4A.

Referring to FIG. 4B, an exemplary trigger 408 is illustrated. Thetrigger 408 depicted in FIG. 4A includes one opening 430 into which aclinician can insert his/her fingers. A trigger, however, may have morethan one opening. Additionally, a trigger may also be comprised of astraight or non-linear member without any openings. Furthermore, atrigger may be in the shape of a button capable of being depressed. Aslong as the trigger, either alone or in conjunction with the handleframe, is ergonomically correct and comfortable for the clinician, thetrigger may have a variety of sizes and shapes.

The trigger 408 illustrated in FIG. 4B includes a trigger pin 428 thatextends vertically from the top of the trigger 408. The trigger pin 428may be formed of a metal, such as a copper alloy (for example, brass orbronze, particularly C 630 nickel aluminum bronze), and may include afrusto-conically shaped end to facilitate insertion into the handleframe 404. The trigger pin 428, which cooperates with the groove in thebarrel cam cylinder 420, acts as a follower for the barrel cam. Thetrigger 408 also includes a pair of sliders 432 protruding laterallyfrom the proximal end of the trigger 408 and a pair of sliders 436protruding laterally from the distal end of the trigger 408. When thetrigger 408 is located within the handle assembly 108, the sliders 432,436 sit and slide in corresponding grooves within the handle frame 404.The trigger 408 also includes a post 440 extending vertically from thetop of trigger 408, and preferably from the distal end of the top of thetrigger 408. The post 440 connects to spring assembly 412.

The handle assembly 108, including the trigger 408 and barrel camcylinder 420 discussed above is an example of a mechanical actuationmeans to rotate the inner sheath assembly. In an alternate embodiment,the actuation means may comprise electromechanical components. Forexample, the actuation means may comprise an electric motor (not shown)having a driven shaft that is directly or indirectly coupled to theinner sheath, the barrel cam cylinder, the trigger pin, and/or anycombination thereof. The motor's shaft may be indirectly coupled to theinner sheath by one or more gears discussed hereinbefore. The motor maybe controlled by a switch, thereby causing the inner sheath to rotate ina clockwise and/or a counter-clockwise direction upon actuating a switchthat may also act as the trigger. The electric motor may be either adirect current (DC) motor or an alternating current (AC) motor.Accordingly, the motor may be powered by a DC source, such as a battery,or an AC source, such as a conventional power cord. Additionally, thoseskilled in the art will appreciate that there are numerous other ways inwhich a surgical device comprising a rotatable sheath may be actuatedand driven.

As mentioned above, the handle assembly 108 may include a strain reliefcomponent 416. The strain relief component 416, as illustrated in FIG.4A, is attached to the distal end of the handle frame 404 and tapersfrom its proximal end toward its distal end. The strain relief component416 also has a lumen passing through it, thereby allowing the sheathassembly 112 to extend there through and into the handle assembly 108.The strain relief component 416 may be constructed of a flexiblematerial such as, Santoprene™ thermoplastic vulcanizate produced byExxonMobil. The material from which the strain relief component is madeand the shape of the strain relief component provide a flexural modulusto protect the flexible shaft as it extends the rigid handle. The lumenof the strain relief may also contain a counter bore that enablesancillary outer sheaths to be docked during device preparations.

Referring to FIGS. 4C, 4D and 4E, there is depicted an elevation view,cross-sectional view and end view of the barrel cam cylinder 420,respectively. As illustrated in FIGS. 4C and 4D, the barrel cam cylinder420 has an exterior surface comprising a cam slot (or channel) 444 thatcooperates with the trigger pin 428 to create the barrel cam. The camslot 444 may create a two dimensional linear and/or non-linear camprofile, which is discussed in further detail below. The barrel camcylinder 420 has a proximal end 448 and a distal end 452 through which alumen 456 extends.

FIG. 4E illustrates the end view of the distal end 452 of the barrel camcylinder 420. The distal end 452 of the lumen 456 of the barrel camcylinder 420 is designed to mate with exterior of the proximal end ofthe inner key 612, which is discussed in further detail below. The crosssection of the distal end 452 of the lumen 456 of the barrel camcylinder 420 is preferably non-circular. For example, one embodiment ofa non-circular lumen includes two chamfered sides 464, wherein onechamfered side 464 is not offset, and the other chamfered side 464 isoffset (e.g., about 8 degrees). Because the distal end of the barrel camcylinder 420 is designed to mate with exterior of the proximal end ofthe inner key 612 and transfer torque from the barrel cam cylinder 420to the inner sheath assembly via the inner key 612, the cross section ofthe exterior of proximal end of the inner key 612 will have acomplimentary profile of the lumen 456. Although the cross sectionalshape of the non-circular lumen is described as having two chamferedsides 464, the disclosure shall not be limited to such shape and mayinclude alternative non-circular shapes, such as a square, rectangle,D-shape, triangle, rhombus, trapezoid, pentagon, hexagon, octagon,parallelogram, ellipse, etc. Alternatively, the inner key could coupleto the outside of the barrel cam cylinder.

The proximal end of the barrel cam cylinder 420 mates with the bushing424. Specifically, the exterior, distal end of the bushing 424 islocated within the proximal end of the lumen 456. Both the exterior,distal end of the bushing 424 and the proximal end of the lumen 456 arecircularly shaped, thereby allowing the bushing 424 and the barrel camcylinder 420 to rotate with respect to one another. The proximal end ofthe exterior of the bushing 424, however, is located within a groovewithin the handle frame 404, thereby preventing the bushing 424 and thebarrel cam cylinder 420 from moving longitudinally within the handleassembly 108.

Referring to FIG. 4F, an exemplary spring assembly 412 is depicted. Thespring assembly 412 includes a constant force spring 472 and a spool474. One end of the constant force spring 472 is connected to the spool474, and the other end of the constant force spring 472 is connected tothe post 440 extending from the trigger 408. As a clinician pulls thetrigger 408 proximally, the sliders 432, 436 travel and slide in thegrooves within the handle frame 404, thereby preventing the trigger 408from moving vertically within the handle assembly 108 and only allowingthe trigger 408 to move along the longitudinal axis of the surgicaldevice 106 from its distal end toward its proximal end and/or viceversa. As the trigger 408 moves proximally, the constant force spring472 uncoils, thereby creating tension and a distally directed force.Accordingly, when the trigger 408 is released by the clinician, theconstant force spring 472 recoils and pulls the trigger 408 back towardsits original and most distal position.

Referring to FIG. 6, there is depicted an elevation view of anembodiment of an assembled sheath assembly 112 of the presentdisclosure. The sheath assembly 112 includes an inner sheath assemblyand an outer sheath assembly. Referring to FIG. 6A, which illustrates anexploded view of the distal end of the sheath assembly 112, andreferring to FIG. 6B, which is an exploded illustration of the proximalend and central portion of the sheath assembly 112, the sheath assembly112 may include may include some or all of the following components: anouter band 636; a guide pin 640; a cutting tip 632; a flexible innersheath 620; a flexible outer sheath 624; an outer jacket 628; an innerkey 612; an outer key 608; and a rigid inner tube 616.

Referring to FIG. 7A, there is depicted an embodiment of the outersheath assembly 602 of the present disclosure. The outer sheath assembly602 includes an outer band 636 located at and attached to the distal endof an elongated flexible outer sheath 624, and an outer key 608 locatedat and attached to the proximal end of the flexible outer sheath 624.The outer band 636 may be attached to the distal end of a flexible outersheath 624 via a weld, an adhesive, a press-fitting technique, aninterlock such as a barbed joint or other known means of attachment. Allsuch attachment techniques within the knowledge of one skilled in theart are considered within the scope of this disclosure. Similarly, theouter key 608 may be attached to the proximal end of the flexible outersheath 624 via a weld, an adhesive, a press-fitting technique, interlocksuch as a barbed joint, or other known means of attachment. Although itis not shown on FIG. 7A, the outer sheath assembly may also include aflexible outer jacket 628 that covers the outer sheath 624 and abuts theouter band 636, thereby providing the outer sheath assembly with arelatively smooth, continuous and uninterrupted exterior profile. Theflexible jacket also contains the egress of blood from the system.

Referring to FIG. 7B, there is depicted an embodiment of the innersheath assembly 604 of the present disclosure. The inner sheath assembly604 includes a cutting tip 632, a flexible inner sheath 620, an innerkey 612, and a rigid inner tube 616. The proximal end of the cutting tip632 is attached to the distal end of a flexible inner sheath 620; thedistal end of an inner tube 616 is attached to the proximal end of theflexible inner sheath 620; and an inner key 612 is attached to theproximal end of the inner tube 616. The means of attaching thesecomponents may include a weld, an adhesive, a press-fitting technique,or other known means of attachment. As will be discussed below, theguide pin 640 couples the outer band 636 with the cutting tip 632, andthe guide pin 640 may be includes with either the inner sheath assembly604 or the outer sheath assembly 602.

It may be preferable for a portion of either the inner sheath 620 and/orthe outer sheath 624 to be rigid and a portion of the outer sheath to beflexible. Both the rigid portion and the flexible portion may beconstructed of materials suitable for insertion into the human body. Forexample, the rigid portion may be constructed of stainless steel, andthe flexible portion may be constructed of a flexible polymer such aspolytetrafluoroethylene or thermoplastic elastomers. Assuming that botha rigid portion and a flexible portion are used, they will form aunitary inner sheath and/or outer sheath. As depicted in FIG. 7B, therigid inner tube 616 is not only attached to the inner key 612, therigid tube 616 also is inserted through the inner key 612 and extendsfrom both the proximal end and distal end of the inner key 612. Theattachment and extension of the rigid tube 616 to the inner key 612allows for an increased amount of torque that can be transferred fromthe barrel cam to the rigid tube 616 via the inner key 612 andeventually to the cutting tip 632 via the inner sheath assembly 604. Theextension of the rigid tube through the handle provides an access pointfor introduction of other medical devices. The extension also provides ameans of controlling blood egress after the lead has been extracted.

It may be preferable that at least a portion of the outer sheath 624 andthe inner sheath 620 be generally flexible in order to accept,accommodate and navigate the patient's vasculature system. In additionto being flexible, the inner sheath 620 may also have a high degree ofstiffness in order to receive the torque transferred from the barrel camcylinder/inner key and transfer sufficient torque to the cutting tip 632discussed in more detail below. The inner sheath 620 (and/or the outersheath 624) may be formed of a polymer extrusion, braided reinforcedpolymer extrusion, coils, bi-coils, tri-coils, laser cut metal tubingand any combination of the above. The inner sheath (and/or the outersheath 624) may be a unitary structure comprised of multiple portions.

Referring to FIG. 8, there is depicted a cross-sectional view of anembodiment of the sheath assembly 112 comprising the inner sheathassembly 604 located within the outer sheath assembly 602. Referring toFIG. 8C, there is depicted an enlarged view of the inner key 612 of theinner sheath assembly 604 located within the outer key 608 of the outersheath assembly 602. As discussed above, the exterior of the inner key612 is designed to mate with lumen 456 of the distal end of the barrelcam cylinder 420. Accordingly, the cross section of the exterior ofproximal end of the inner key 612 will have a profile complimentary tothe distal end of the lumen 456 within the barrel cam cylinder 420. Forexample, assuming the cross section of the distal end 452 of the lumen456 of the barrel cam cylinder 420 is non-circular and has two chamferedsides, wherein one chamfered side is not offset, and the other chamferedside is offset (e.g., about 8 degrees), then the exterior of theproximal end of the inner key 612 will also have a non-circular profilewith two chamfered sides, wherein one chamfered side is not offset, andthe other chamfered side is offset (e.g., about 8 degrees). The innerkey 612 and outer key 608 provide means for rotationally coupling. Theinner key 612 is a means for rotationally coupling the inner sheathassembly 604 to the barrel cam, and the outer key is a means forrotationally coupling the outer shaft assembly to the handle. The innerkey 612 and outer key 608 provide journal bearing for the other key.

As further illustrated in FIG. 8C, the inner key 612 is able to rotatefreely within the outer key 608 due, at least in part, to the distal endof the exterior of the inner key 612 having a circular cross sectionthat mates with a circular cross section of the proximal end of a lumenwithin the outer key 608. Additionally, because the inner key 612 andouter key 608 are loosely coupled, the inner key 612 and outer key 608are able to move longitudinally with respect to one another. Forinstance, supposing the outer key 608 is fixed such that it neitherrotates nor moves longitudinally, the inner key 612 is able to bothrotate and travel longitudinally within the outer key 608. Accordingly,as the barrel cam cylinder 420 rotates, the inner key 612 will rotatewithin the outer key 608, and the inner sheath assembly 604 will rotatewithin the outer sheath assembly 602, including the rotation of thecutting tip 632 within the outer band 636. And the cam slot profile inthe cutting tip 632 controls the longitudinal movement of the innersheath assembly 604 within the outer sheath assembly 602, including thelongitudinal movement of the inner key 612 relative to the outer key 608and the longitudinal movement of the cutting tip 632 relative to theouter band 636.

Continuing to refer to FIG. 8C, the lumen within the outer key 608 islarger toward its proximal end and smaller toward its distal end becausethere is a step down or an abutment in the lumen as it progresses fromthe proximal end to the distal end. Due to the transition from a largerlumen to a smaller lumen within the outer key 608, there is depicted anadjustable gap 610 between the distal end of the inner key 612 and theabutment within the distal end of the larger lumen in the outer key 608.This gap increases, decreases and/or remains the same according to thecam slot profile of the cutting tip 632. The abutment in the outer key608 insures that the inner key 612 will only travel a limitedlongitudinal distance within the outer key 608, thereby limiting theinner sheath assembly 604 potential longitudinal movement within theouter sheath assembly 602, including limiting the longitudinal movementof the cutting tip 632 relative to the outer band 636 in the distaldirection.

Referring to FIG. 8A, there is depicted an enlarged cross-sectional viewof the distal end of the sheath assembly 112 with the inner sheathassembly 604 coupled with the outer sheath assembly 602 via guide pin640, wherein the blade 822 of the cutting tip 632 is in a refractedposition and located within the outer sheath assembly 602. As discussedabove, the distal end of the outer sheath assembly 602 includes an outerband 636, which may be constructed of a biocompatible metal, such asstainless steel, and polished so that it is generally smooth and evenlyrounded at its most distal point, thereby allowing it to act as adilator when pressed and forced against tissue. The distal end 822 ofcutting tip 632 includes a cutting surface capable of cutting tissue.The inner sheath assembly 604 is coupled to the outer sheath assembly602 through the cutting tip 632 and the outer band 636, respectively,via guide pin 640. One end of the guide pin 640 is fixed within theouter band 636, and the other end of the guide pin 640 is located withinthe cam slot 814 of the cutting tip 632. As the inner sheath 620rotates, upon actuation of the trigger assembly discussed above, thecutting tip 632 also rotates because the inner sheath 620 is fixedlyattached to the cutting tip 632. As the cutting tip 632 rotates, thecutting tip 632 may also extend distally in the direction of the arrow(→) according to the profile of the cam slot 814 as depicted in FIG.8A′. As the cutting tip 632 extends distally and rotates, the guide pin640 and the outer sheath assembly 602, particularly the outer band 636,remain stationary. Thus, as the cutting tip 632 extends distally (andpotentially retracts proximally according to the cam slot profile) androtates, the cutting surface at the distal end 822 of the cutting tip632 is able to perform a slicing action against the tissue and cut it.

Again, FIG. 8A depicts the cutting tip 632 within a retracted (andpotentially un-actuated) position because the cutting tip 632 is in aproximal position. Stated differently, the distal end 822 of the cuttingtip 632 of FIG. 8A is located within the interior of the outer sheathassembly 602, particularly the outer band 636, and does not extendbeyond the distal end of the outer band 636. With reference to FIG. 8A′,the cutting tip 632 is depicted in an extended (and actuated) positionbecause the cutting tip 632 is extending beyond the distal end of theouter sheath assembly 602 and the outer band 636.

FIG. 3 depicts the distal portion of the flexible outer sheath andflexible inner sheath of FIG. 8A surrounding a lead 330 within apatient's vein 334 with the cutting tip 632 in its extended position.The circumferential nature of the cutting surface (e.g., notched blade)at the distal end of the cutting tip 632 causes the surgical device toact as a coring device, thereby cutting tissue 338 either partially(i.e., less than 360 degrees) or completely (i.e., 360 degrees) aroundthe lead or implanted object being extracted. The amount of tissue thatthe cutting surface cuts depends upon the size, shape and configurationof the lead, as well as the diameter and thickness of the circularcutting blade. For example, if the diameter of the circular cuttingsurface is substantially greater than the diameter of the lead, then thecutting surface will cut and core more tissue in comparison to a cuttingsurface having a smaller diameter. Once the desired cut has been made,the operator releases trigger and the cutting tip 632 (including thecutting surface) returns to a retracted position. Upon the cuttingsurface returning to a retracted position, the distal tip of the outerband 636 (and/or other portions of the outer sheath assembly) safelyacts as a dilating device, thereby stretching tissue as the outer sheathassembly move over the lead or implanted object to be extracted.

With each full squeeze of the trigger, the cutting tip (and innersheath) will rotate clockwise and counterclockwise while extending andretracting. The cutting tip (and inner sheath) retracts into the tip ofthe outer sheath when the trigger is fully compressed and/or remainsretracted at the release of the trigger after a full squeeze of thetrigger. If the trigger is partially squeezed, it will not reset and thecutting tip (and inner sheath) will reverse its motion upon release ofthe trigger, returning the blade to the retracted position. The returnto the fully returned trigger position results in a rotation of about 35degrees that due to the profile at the distal cam, which retains thecutting in the sheathed position.

Although the inner sheath and outer sheath are coupled to one anothervia the cutting tip, the outer band, and the guide pin, the inner sheathassembly and outer sheath assembly may be coupled to one another inother ways. Stated differently, those of skill in the art willunderstand how to make and use the disclosed aspects, embodiments,and/or configurations after understanding the present disclosure tocouple the sheaths in a manner to allow a cutting surface to extend androtate beyond the distal end of the outer sheath. All suchconfigurations within the knowledge of one skilled in the art areconsidered within the scope of this disclosure.

With reference to FIGS. 9A, 9B and 9C, an exemplary outer band 636 isdepicted. The outer band 636 may be a sleeve in the general shape of ahollow cylinder. Although the exterior of the outer band 636 isnon-uniform, it may be uniform. The interior of the outer band 636 isnon-uniform. For example, the interior of the outer band 636 includes anabutment 916 to prevent the cutting tip (not shown in FIGS. 9A, 9B and9C) from traveling further from the proximal end 912 to the distal end908 within the outer band 636. The outer band 636 also includes a hole904 for receipt and possible attachment of a guide pin (not shown inFIGS. 9A, 9B and 9C) which protrudes radially inward. As discussed inmore detail above, the guide pin engages the cam slot of the cuttingtip. The size, shape and configuration of the outer band 636 may differdepending upon how it is attached to the flexible outer sheath. Asdiscussed above, the outer sheath may be stationary. If so, the outerband 636 and the guide pin remain stationary as the cutting tip moves(e.g., rotates and travel longitudinally) relative thereto. The outerband may also contain a journal bearing surface to align the cuttingblade during actuation and provide a surface to disengage the tissue atthe retraction of the cutting blade within the device.

With reference to FIGS. 10A, 10B, 10C and 10D, an exemplary cutting tip632 is depicted. The cutting tip 632 has a generally hollow cylindricalshape. The cutting tip 632 comprises a proximal portion 1024, anintermediate portion 1028, and a distal portion 1032. The outsidediameter of the proximal portion 1024 is sized to allow it to beinserted to and/or engage (or otherwise attached to) the interiordiameter of the inner flexible sheath (not shown in FIGS. 10A, 10B, 10Cand 10D). The distal end of cutting tip 632 comprises a cutting surface1012 having a serrated, sharp blade profile. The intermediate portion1028 comprises a channel (or cam slot) 1016 cut within its exteriorsurface. As the inner flexible sheath rotates and moves within the outersheath—from its proximal end to distal end—the outer sheath and pin mayremain stationary. If so, the inner sheath (not shown), which isconnected to cutting tip 632, forces the cutting tip 632 to rotate. Thecam slot 1016 engages the guide pin, and the shape and profile of thecam slot 1016 controls the rate and distance with which the cutting tip632 travels longitudinally. That is, the configuration of the cam slot1016 controls the cutting tip's direction and amount of longitudinaltravel, such as moving distally toward an extended position and/orproximally toward a retracted position, while the cutting tip 632rotates in either a clockwise or counter-clockwise direction.

Referring again to FIGS. 10A, 10B, 10C and 10D, the cutting tip 632 mayalso comprise a step up 1020 such that the diameter of the intermediateportion 1028 is greater than the distal portion 1032. As the cutting tip632 rotates, and the cutting surface 1012 extends beyond the distal endof the outer band into an extended position, the step up 1020 of thecutting tip 632 contacts the abutment of the outer band, therebylimiting the distance that the cutting tip 632 may travel and/or mayprevent the cutting tip 632 from exiting or extending beyond the distaltip of the outer sheath assembly, particularly the outer band, in theevent that the pin is sheared.

The profile of the cam slot in the cutting tip may have variousconfigurations, such as those disclosed in U.S. patent application Ser.No. 13/834,405 filed Mar. 15, 2013 and entitled Retractable Blade ForLead Removal Device, which is hereby incorporated herein by reference inits entirety for all that it teaches and for all purposes. For example,the cam slot may have a substantially linear profile, a substantiallysinusoidal profile, or a combination of individual and/or multiplelinear and non-linear profiles. Additionally, the cam slot may have anopen and continuous configuration, thereby allowing the cutting tip tocontinuously rotate, or the cam slot may have a closed and discontinuousconfiguration such that when the cutting tip reaches its fully extendedposition, the trigger assembly must be released or reversed so that thecutting tip returns to initially retracted position before beingre-actuated. For instance, the cam slot 1016 in FIG. 10A isdiscontinuous because the cam slot does not travel around the entirecircumference of the exterior of the cutting tip 632. Although certainfigures in this disclosure only illustrate either the open or closed camslot configuration, either configuration may be used with any of theinner cam embodiments disclosed and/or discussed herein and areconsidered within the scope of this disclosure. Furthermore, varioustypes of cams, such as a partial lobe cam (which includes a cam slotsurrounding less than 360 degrees of the circumference of the exteriorsurface of the cutting tip), a single lobe cam (which includes a camslot surrounding 360 degrees of the circumference of the exteriorsurface of the cutting tip), double lobe cams (which includes a cam slotsurrounding 720 degrees of the circumference of the exterior surface ofthe cutting tip) and/or other multiple lobe cams.

The distal end of cutting tip 632 may comprise a cutting surface 1012having different blade profiles, such as those disclosed in U.S. patentapplication Ser. No. 13/834,405 filed Mar. 15, 2013 and entitledRetractable Blade For Lead Removal Device, which is hereby incorporatedherein by reference in its entirety for all that it teaches and for allpurposes. For example, the plane of the cutting surface 1012 of thedistal end of the cutting tip depicted in the figures of this disclosureis parallel to the plane of the proximal end of the cutting tip. Theplane of the cutting surface, however, may be offset (0 degrees to 90degrees) from the plane of the proximal end of the cutting tip. Also, asdiscussed above, the profile of the cutting surface 1012 in FIGS.10A-10D has a plurality of serrations. The profile of the cuttingsurface 1012 need not be serrated and may comprise other configurations,such as a constant and/or smooth sharp profile. The profile of thecutting surface 1012 in FIGS. 10A-10D has a plurality of six (6)serrations. However, it may be preferable to have less than or more thansix (6) serrations. It may also be preferable to have between five (5)and seven (7) serrations, or between four (4) and eight (8) serrations,or between six (6) and ten (10) serrations.

Although the cutting surface 1012 illustrates a certain number ofserrations, FIGS. 10A-10D are not intended to represent the only numberand type of serrations that may be included in a serrated cuttingsurface. Depending upon the size of the surgical device, including thesheaths, and cutting tip, those of skill in the art will understand howto make and use the disclosed aspects, embodiments, and/orconfigurations after understanding the present disclosure to adjust thenumber, size and configurations of the serrations. All suchconfigurations within the knowledge of one skilled in the art areconsidered within the scope of this disclosure. Furthermore, theserrations may comprise a myriad of different shapes and configurations,including but not limited to any variation of a square, rectangle,rhombus, parallelogram, trapezoid, triangle, circle, ellipse, kite, etc.

As discussed above, FIGS. 10A, 10B and 10D depict the intermediateportion 1028 of the cutting tip 632 having a cam slot (or channel) 1016cut within its exterior surface, and FIGS. 4C and 4D depict the barrelcam cylinder 420 having a channel (or cam slot) 444 on its exteriorsurface that creates a non-linear cam profile. Referring to FIG. 11there is depicted a two-dimensional illustration of the profile of thecam slot 1016 for the cutting tip 632 at the top of the figure and atwo-dimensional illustration of the profile of the cam slot 444 for thebarrel cam cylinder 420 at the bottom of the figure. The horizontalaxis, which is the same for the top illustration and the bottomillustration, is the degree(s) of rotation of the cutting tip 632 andthe barrel cam cylinder 420. For example, assuming that the profile ofthe cam slot 1016 in the cutting tip 632 is discontinuous, as depictedin FIG. 10A, the cutting tip 632 will rotate less than 360 degrees. Itmay be preferable for the cutting tip 632 to rotate between 5 and 355degrees, 180 degrees and 355 degrees, 210 degrees and 325 degrees, 240degrees and 295 degrees, or 270 degrees and 275 degrees. It may also bepreferable for the cutting tip 632 rotate about 180, 185, 190, 200, 205,210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275,280, 285, 290, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350 or355 degrees. The first half of a trigger pull results in about a 273°rotation in one direction—clockwise when looking from the handle to thetip—thereby returning the cam blade to the sheathed position. The secondhalf of the trigger pull results in about a 273° in the oppositedirection—counter-clockwise when looking from the handle to thetip—thereby, returning the cutting blade to the sheathed position again.The blade remains in the sheathed position for the full return of thetrigger to the forward position. The vertical axis for the topillustration is the amount of longitudinal movement, if any, of thecutting tip 632 including its cutting surface. The vertical axis for thebottom illustration is the amount of longitudinal displacement (ininches) of the trigger assembly (and trigger pin).

Referring to FIG. 11 in combination with FIGS. 5A-5E, the followingdiscussion explains the interaction between the rotation of the barrelcam cylinder 420, the rotation of the cutting tip 632, the longitudinalmovement of the handle (via the position of its trigger pin 428), andthe longitudinal movement of the cutting tip 632. The following is adescription of the positions CT1-CT6 of the guide pin 640 within the camslot of the cutting tip 632:

-   -   CT1—the guide pin 640 is at its home position within the cam        slot 1016 of the cutting tip 632, and the cutting tip 632 is in        a retracted position within the outer sheath assembly 602        (including the outer band 636);    -   CT2—the cutting tip 632 has rotated in a clockwise direction        over the guide pin 640 within the cam slot 1016 for about half        of its predetermined rotation, and the cutting tip 632 is in its        most extended position outside the outer sheath assembly 602;    -   CT3—the cutting tip 632 has completed its rotation in a        clockwise direction over the guide pin 640 within the cam slot        1016, and the cutting tip 632 is in a retracted position within        the outer sheath assembly 602;    -   CT4—the cutting tip 632 has rotated in a counter-clockwise        direction over the guide pin 640 within the cam slot 1016 for        about half of its predetermined rotation, and the cutting tip        632 is in its most extended position outside the outer sheath        assembly 602;    -   CT5—(not shown) the cutting tip 632 has completed its rotation        in a counter-clockwise direction over the guide pin 640 within        the cam slot 1016, and the cutting tip 632 is in a retracted        position within the outer sheath assembly 602; and    -   CT6—the cutting tip 632 has completed its rotation in a        counter-clockwise direction over the guide pin 640 within the        cam slot 1016, and the cutting tip 632 is in its most retracted        position within the outer sheath assembly 602.

The positions CT1-CT6 of the guide pin 640 within the cam slot of thecutting tip 632 correspond with positions BC1-BC6 of the trigger pin 428within the cam slot of the barrel cam cylinder 420. The following is adescription of the positions BC1-BC6 of the trigger pin 428 within thecam slot of the barrel cam cylinder 420:

-   -   BC1—the trigger pin 428 (along with the trigger 408 of the        trigger assembly 106) is at its home position within the cam        slot 444 of the barrel cam cylinder 420;    -   BC2—the trigger pin 428 has moved longitudinally in a proximal        direction, thereby causing the barrel cam cylinder 420 to rotate        in a clockwise direction; at this point, the barrel cam cylinder        has rotated clockwise about half of its predetermined amount;    -   BC3—the trigger pin 428 has moved about half of its longitudinal        movement is continuing to move longitudinally in a proximal        direction and the barrel cam cylinder 420 has completed its        rotation in a clockwise direction;    -   BC4—the trigger pin 428 is moving longitudinally in a proximal        direction, thereby causing the barrel cam cylinder 420 to rotate        in a counter-clockwise direction; at this point, the barrel cam        cylinder has rotated counter-clockwise about half of its        predetermined amount;    -   BC5—the trigger pin 428 has moved about its entire longitudinal        movement in a proximal direction and the barrel cam cylinder 420        has completed its rotation in a counter-clockwise direction; and    -   BC6—the trigger pin 428 has moved longitudinally in a distal        direction, thereby causing the barrel cam cylinder 420 to rotate        any remaining amount in a counter-clockwise direction.

Continuing to refer to FIG. 11 and FIGS. 5A-5E, when the triggerassembly 106, particularly the trigger 408, is at its initial, distalposition, the trigger pin 428 is at its home position (BC1). Referringto the top illustration of FIG. 11, at the time the trigger pin 428 isat its home position (BC1), the guide pin 640 in the sheath assembly 112is at its initial position (CT1), and the cutting tip 632 is at aretracted (or recessed) position within the outer sheath assembly 602.Upon a clinician pulling the trigger 408 and moving the trigger pin 428proximally, both the barrel cam cylinder 420 and the cutting tip 632rotate in a clockwise direction (from the proximal perspective of barrelcam cylinder). Upon the cutting tip 632 rotating adjacent the guide pin640 from position CT1 to CT2, the profile of the cam slot in the cuttingtip 632 causes the cutting tip 632 to move longitudinally in a distaldirection from a retracted position to an extended position. When thetrigger pin 428 is at position BC2, (i) the barrel cam cylinder 420 andthe cutting tip 632 have rotated about half of its predeterminedallowable rotation in the clockwise direction, (ii) the guide pin 640 isat position CT2, and (iii) the cutting tip 632 is at its most extendedposition.

As the clinician continues to pull the trigger, the trigger pin 428continues to move proximally, and the barrel cam cylinder 420 and thecutting tip 632 continue to rotate in a clockwise direction.Specifically, the cutting tip 632 rotates adjacent the guide pin 640,and the profile of the cam slot in cutting tip 632 causes the cuttingtip 632 to move longitudinally from position CT2, which is an extendedposition, to CT3, which is a recessed position. When the trigger pin 428is at position BC3, (i) the barrel cam cylinder 420 and the cutting tip632 have rotated about half of their predetermined allowable rotation inthe clockwise direction, (ii) the guide pin 640 is at position CT3, and(iii) the cutting tip 632 is at a retracted position within the outersheath assembly 602 (including the outer band 636).

Referring to the top illustration of FIG. 11, the cam slot in thecutting tip 632 extends beyond position CT3. As discussed above, theinner sheath assembly and outer sheath assembly may both be flexible. Inorder to accommodate for the potentially additional length created bythe flexing of the sheath assemblies, as well as accommodating formanufacturing tolerances, the cam slot 1016 in the cutting tip 632extends beyond position CT3. For example, if during use of the surgicaldevice, the home position of the guide pin 640 is slightly to the rightof position CT1, rather than exactly at position CT1, then the extendedlength of the cam slot allows the guide pin 640 to travel to the rightof position CT3, thereby allowing the cutting tip to rotate its totalamount of allowable rotation in the clockwise direction withoutobstruction.

As the trigger pin 428 moves from position BC1 to BC3 in the barrel camcylinder 420, and the barrel cam cylinder 420 rotates in a clockwisedirection, the trigger pin 428 rides along the inside edge of the camslot 444 in the barrel cam cylinder 420. However, when the trigger pin428 moves from position BC3 to BC5 in the barrel cam cylinder, thebarrel cam cylinder 420 rotates in a counter-clockwise direction, andthe trigger pin 428 rides along the outside edge of the cam slot 444 inthe barrel cam cylinder 420.

When the guide pin 640 reaches position CT3 in the cutting tip 632 andthe trigger pin 428 reaches position BC3 in the barrel cam cylinder 420,the trigger assembly 106, particularly the trigger 408, has onlytraveled about half of its predetermined allowable distance in thelongitudinal direction. As the user continues to pull the triggerassembly 106, the trigger 408 and trigger pin 428 continue to moveproximally. As this occurs, the barrel cam cylinder 420 and the cuttingtip 632 switch from rotating in a clockwise direction to rotating in acounter-clockwise direction. And because the cutting tip 632 switchesfrom rotating in a clockwise direction to a counter-clockwise directionas the cutting tip 632 moves past position CT3 to CT4 adjacent the guidepin 640, the cutting tip 632 moves from a retracted position within theouter sheath assembly 602 (including the outer band 636) to an extendedposition or partially extended position outside the outer sheathassembly 602 (including the outer band 636). When the trigger pin 428 isat position BC4, (i) the barrel cam cylinder 420 and the cutting tip 632have rotated counter-clockwise for slightly less than half (or half) ofits predetermined allowable distance, (ii) the guide pin 640 is atposition CT4, and (iii) the cutting tip 632 is at its most extendedposition.

As the user pulls the trigger 408 further, the trigger pin 428 continuesto move proximally from position BC4 to position BC5 in the barrel camcylinder 420, thereby causing the barrel cam cylinder 420 and cuttingtip 632 to continue rotating in a counter-clockwise direction.Specifically, the cutting tip 632 rotates adjacent the guide pin 640from position CC4 toward CC6, and the profile of the cam slot in thecutting tip 632 causes the cutting tip 632 to move from an extendedposition to a retracted position. When the trigger pin 428 is located atposition BC5 in cam slot of the barrel cam cylinder 420, the trigger 408has reached the end of its longitudinal movement in the proximaldirection. Upon the trigger pin 428 surpassing position BC5 in the camslot of the barrel cam cylinder 420, the constant force spring causesthe trigger 408 and trigger pin 428 to reverse direction and traveltoward its distal position.

As discussed above, for a discontinuous cam slot in the cutting tip 432,the cutting tip 432 rotates less than 360 degrees in either theclockwise or counter-clockwise direction. Assuming that thepredetermined amount of allowable rotation is about 275 degrees, theamount of angular rotation by the barrel cam cylinder 420 in theclockwise direction from BC1 to BC3 and by the cutting tip 632 from CT1to CT3 is about 275 degrees. The amount of angular rotation by thebarrel cam cylinder 420 in the counter-clockwise direction from BC3 toBC5 and the cutting tip 632 from CT3 to CT3 is greater than 275 degreesby about nine degrees. This additional rotation (or over rotation) bythe barrel cam cylinder 420 and the cutting tip 632 in thecounter-clockwise direction ensures that the cutting tip 632, includingits cutting surface, is covered by the outer sheath assembly 602,particularly the outer band 636. Upon the trigger 408 reaching the endof its longitudinal movement in the proximal direction at position BC5,the barrel cam cylinder 420 and cutting tip 632 continue to move in acounter-clockwise direction to position BC6 and position CT6,respectively. Specifically, barrel cam cylinder 420 rotatescounter-clockwise form position BC5 to BC6 about 17 degrees, therebycausing the cutting tip 632 to rotate counter-clockwise the same amountfrom position CT5 (not shown) to position CT6, which is the cuttingtip's most recessed position.

When trigger pin 408 is at position BC6 in the barrel cam cylinder 420and the guide pin 640 is at position CT6 within the cutting tip 632, thebarrel cam cylinder 420 and cutting tip 632 still need to return totheir home positions BC1, CT1. In order for the barrel cam cylinder 420and cutting tip 632 to return to their home positions BC1, CT1, thebarrel cam cylinder 420 and cutting tip 632 rotate about 34.5 degrees inthe clockwise direction from position BC6 to BC1 and from CT6 to CT1.When the trigger pin 428 is back to its home position (BC1), (i) thebarrel cam cylinder 420 and cutting tip 632 have rotated counter-clockwise 307.6 degrees (and rotated clockwise 34.5 degrees), (ii) the guidepin 640 is at position CT1, and (iii) the cutting tip 632 is at arecessed position. That is, the cutting tip 632 (and barrel cam cylinder420) have rotated a net 273.1 degrees in the clockwise direction in aretracted (home)-extended-retracted sequence of positions and 273.1degrees in the counter-clockwise direction aretracted-extended-retracted (home) sequence of positions, even thoughthe cutting tip 632 (and barrel cam cylinder 420) rotated in both acounter-clockwise direction and a clockwise direction in aretracted-extended-retracted (home) sequence of positions. The user maythen repeat the process, if so desired.

Embodiments according to this disclosure provide a surgical device thatincludes a sheath assembly, which can be deployed safely within avascular system of a patient and separate implanted objects, such asleads, from a patient's vasculature system. FIG. 12 depicts a surgicaldevice 1206 having a sheath assembly 1212 inserted within an exemplarypatient 1204. The sheath assembly 1212 surrounds an implanted lead (notshown) running along the left innominate vein past the SVC and connectedinto, or about, the right ventricle of the heart. Upon surrounding thelead with the sheath assembly 1212, the user of the surgical device 1206may actuate the handle assembly 1208, thereby rotating and extending acutting blade (not shown) beyond the distal end of the sheath assembly1212 to dilate, separate and/or cut the tissue surrounding the leadwithin the patient's SVC.

The cutting blade may extend from and retract into the sheath uponactuation of the handle assembly according to the profile of the camslot in the cutting tip disclosed below. The cutting blade may rotate ina first, or clockwise, direction upon an initial, or first, actuation ofthe handle assembly per the profile of the cam slot in the barrel camcylinder discussed below. When the clinician releases the handleassembly, the cutting blade is ensured to remain or return within thesheath assembly 1212, thereby allowing the clinician to force andadvance the distal portion of the sheath assembly against additionaluncut tissue. The cutting blade may rotate in a second, orcounter-clockwise, direction upon a subsequent, or second, actuation ofthe handle assembly per the profile of the cam slot in the barrel camcylinder discussed below. Each time actuation occurs, the proximalportion of the implanted lead and/or surrounding tissue enters furtherinto a hollow passageway within the sheath assembly 1212. This processis again repeated until the implanted lead and/or surrounding tissue iscompletely or substantially dilated, separated, and/or cut from thetissue attached to the SVC. At that time, the implanted lead may safelybe removed from the patient's SVC.

With reference to FIG. 13, an exemplary surgical device 1206 isdepicted. The surgical device 1206 includes a handle assembly 1208 and aflexible sheath assembly 1212. The flexible sheath assembly 1212, whichis discussed in more detail below, generally includes a flexible innersheath assembly (not shown) located within a flexible outer sheathassembly. It may be preferable for the outer sheath to remain stationarywhile the inner sheath is capable of moving (e.g., rotating andextending) with respect to the outer sheath. The inner sheath and outersheath can both be flexible, rigid or a combination thereof.

With reference to FIG. 15A, an exemplary handle assembly 1208 isdepicted. The handle assembly 1208 may include some or all of thefollowing components: a handle frame 1504, a trigger 1508, a springassembly 1512, a strain relief component 1516, a barrel cam assembly1519, a bushing 1524 and an end cap 1527. The handle frame 1504 may beconstructed of a singular component or multiple component, such as twohalves as illustrated in FIG. 15A.

Referring to FIG. 15B, an exemplary trigger 1508 is illustrated. Thetrigger 1508 depicted in FIG. 15B includes one opening 1530 into which aclinician can insert his/her fingers. A trigger, however, may have morethan one opening. Additionally, a trigger may also be comprised of astraight or non-linear member without any openings. Furthermore, atrigger may be in the shape of a button capable of being depressed. Aslong as the trigger, either alone or in conjunction with the handleframe, is ergonomically correct and comfortable for the clinician, thetrigger may have a variety of sizes and shapes.

The trigger 1508 illustrated in FIG. 15B includes a trigger pin 1528that extends vertically from the top of the trigger 1508. The triggerpin 1528 may be formed of a metal, such as a copper alloy (for example,brass or bronze, particularly C 630 nickel aluminum bronze), and mayinclude a frusto-conically shaped end to facilitate insertion into thehandle frame 1504. The trigger pin 1528, which cooperates with a groovein a barrel cam cylinder of the barrel cam assembly 1519, acts as afollower for the barrel cam cylinder. The trigger 1508 also includes apair of sliders 1532 protruding laterally from the proximal end of thetrigger 1508 and a pair of sliders 1536 protruding laterally from thedistal end of the trigger 1508. When the trigger 1508 is located withinthe handle assembly 1208, the sliders 1532, 1536 sit and slide incorresponding grooves within the handle frame 1504. The trigger 1508also includes a post 1540 extending vertically from the top of trigger1508, and preferably from the distal end of the top of the trigger 1508.The post 1540 connects to the spring assembly 1512.

As mentioned above, the handle assembly 1208 may include a strain reliefcomponent 1516. The strain relief component 1516, as illustrated in FIG.15A, is attached to the distal end of the handle frame 1504 and tapersfrom its proximal end toward its distal end. The strain relief component1516 also has a lumen passing through it, thereby allowing the sheathassembly 1212 to extend there through and into the handle assembly 1208.The strain relief component 1516 may be constructed of a flexiblematerial such as, Santoprene™ thermoplastic vulcanizate produced byExxonMobil. The material from which the strain relief component is madeand the shape of the strain relief component provide a flexural modulusto protect the flexible shaft as it extends the rigid handle. The lumenof the strain relief may also contain a counter bore that enablesancillary outer sheaths to be docked during device preparations.

Referring to FIG. 15C, an exemplary barrel cam assembly 1519 isillustrated. The barrel cam assembly 1519 includes a barrel cam cylinder1520 that rotatably carries a follower guide 1521. As described infurther detail below, the barrel cam cylinder 1520 and the followerguide 1521 cooperate with the trigger pin 1528 to create the barrel cam.

The barrel cam cylinder 1520 may be formed from one or morebiocompatible materials, such as polyethylene-filled Delrin®, stainlesssteel, anodized aluminum, brass, titanium, or the like. As illustratedin FIG. 15D, the barrel cam cylinder 1520 has an exterior surfacecomprising a cam groove (or slot or channel) 1544 that translatablyreceives the trigger pin 1528. FIG. 15E depicts a two-dimensionalillustration of the profile of the cam slot 1544 for the barrel camcylinder 1520. The cam slot 1544 defines a generally “hourglass”-like or“figure eight”-like path for the follower (that is, the trigger pin1528). As described in further detail below, the trigger pin 1528traverses about half of the cam slot 1544 when an initial, or first,actuation is applied to the trigger 1508, and the trigger pin 1528traverses the remainder of the cam slot 1544 (that is, about half of thecam slot 1544) when a subsequent, or second, actuation is applied to thetrigger 1508. In each case, and as described in further detail below,the follower guide 1521 causes the trigger pin 1528 to travel straightthrough the intersection (or crossing portion) 1545 of the cam slot 1544during each actuation of the trigger 1508. Stated another way, thefollower guide 1521 causes the trigger pin 1528 to travel from a firstleg 1547 of the cam slot 1544 to a second parallel leg 1549 of the camslot 1544, and then from a third leg 1551 of the cam slot 1544 to afourth parallel leg 1553 of the cam slot 1544.

FIGS. 15F and 15G illustrate a longitudinal-sectional view and across-sectional view, respectively, of the barrel cam cylinder 1520. Thebarrel cam cylinder 1520 has a proximal end 1548 and a distal end 1552through which a lumen 1556 extends. The distal end 1552 of the lumen1556 of the barrel cam cylinder 1520 is designed to mate with exteriorof the proximal end of the inner key 1612, which is discussed in furtherdetail below. The cross section of the distal end 1552 of the lumen 1556of the barrel cam cylinder 1520 is preferably non-circular. For example,one embodiment of a non-circular lumen includes two chamfered sides1564, wherein one chamfered side 1564 is not offset, and the otherchamfered side 1564 is offset (e.g., about 8 degrees). Because thedistal end of the barrel cam cylinder 1520 is designed to mate withexterior of the proximal end of the inner key 1612 and transfer torquefrom the barrel cam cylinder 1520 to the inner sheath assembly via theinner key 1612, the cross section of the exterior of proximal end of theinner key 1612 will have a complimentary profile of the lumen 1556.Although the cross sectional shape of the non-circular lumen isdescribed as having two chamfered sides 1564, the disclosure shall notbe limited to such shape and may include alternative non-circularshapes, such as a square, rectangle, D-shape, triangle, rhombus,trapezoid, pentagon, hexagon, octagon, parallelogram, ellipse, etc.Alternatively, the inner key could couple to the outside of the barrelcam cylinder.

The proximal end of the barrel cam cylinder 1520 mates with the bushing1524. Specifically, the exterior, distal end of the bushing 1524 islocated within the proximal end of the lumen 1556. Both the exterior,distal end of the bushing 1524 and the proximal end of the lumen 1556are circularly shaped, thereby allowing the bushing 1524 and the barrelcam cylinder 1520 to rotate with respect to one another. The proximalend of the exterior of the bushing 1524, however, is located within agroove within the handle frame 1504, thereby preventing the bushing 1524and the barrel cam cylinder 1520 from moving longitudinally within thehandle assembly 1208.

The follower guide 1521 may be formed from one or more biocompatiblematerials, such as stainless steel, anodized aluminum, titanium, or thelike. In some embodiments, the follower guide 1521 and the barrel camcylinder 1520 have a relatively high coefficient of frictiontherebetween. The follower guide 1521 is rotatably carried by the barrelcam cylinder 1520; as such, it may be preferable for the follower guide1521 to be a dissimilar material from the barrel cam cylinder 1520 toinhibit galling. In some embodiments, the inner surface of the followerguide 1521 may have a slightly different cross-sectional shape than thatof the outer surface of the barrel cam cylinder 1520 to inhibitunintentional rotation of the follower guide 1521 relative to the barrelcam cylinder 1520. For example, the outer surface of the barrel camcylinder 1520 may have a circular cross-sectional shape, and the innersurface of the follower guide 1520 may have a slightly non-circularcross-sectional shape.

As illustrated in FIG. 15H, the follower guide 1521 is a generallycylindrical component that includes an aperture 1565. The trigger pin1528 extends through the aperture 1565 to enter the cam slot 1544 of thebarrel cam cylinder 1520. As explained in further detail below, firstand second diagonally extending walls 1567 and 1569 of the aperture 1565(that is, diagonally extending relative to the longitudinal axis of thebarrel cam assembly 1519) engage the trigger pin 1528 to cause thetrigger pin 1528 to travel straight through the intersection 1545 of thecam slot 1544. In additional and as explained in further detail below,the follower guide 1521 rotates relative to the barrel cam cylinder 1520to appropriately position the first and second diagonally extendingwalls 1567 and 1569 during first and second actuations of the trigger1508. The aperture 1565 includes first and second longitudinallyextending walls 1571 and 1573 (that is, walls extending parallel to thelongitudinal axis of the barrel cam assembly 1519) that engage thetrigger pin 1528 to facilitate rotation of the follower guide 1521relative to the barrel cam cylinder 1520.

The first and second diagonally extending walls 1567 and 1569, the firstand second longitudinally extending walls 1571 and 1573, and the otherwalls that define the aperture 1565 extend from an inner surface to anouter surface of the follower guide 1521. In some embodiments, thesewalls extend in a radial direction between the inner surface and theouter surface. In some embodiments, these walls extend diagonallybetween the inner surface and the outer surface (that is, these wallsform a chamfer between the inner surface and the outer surface).

Referring now to FIGS. 15J and 15K, the barrel cam assembly 1519 furtherincludes a relative rotation-inhibiting mechanism 1575 that, as the nameimplies, inhibits some rotation of the follower guide 1521 relative tothe barrel cam cylinder 1520. Generally, the relativerotation-inhibiting mechanism 1575 permits the follower guide 1521 tooccupy a first relative rotation-inhibiting position and a secondrelative rotation-inhibiting position. In the first relativerotation-inhibiting position, the mechanism 1575 permits the followerguide 1521 to rotate in a first direction relative to the barrel camcylinder 1520 (that is, toward the second relative rotation-inhibitingposition) and inhibits rotation of the follower guide 1521 relative tothe barrel cam cylinder 1520 in a second direction. In the secondrelative rotation-inhibiting position, the mechanism 1575 permits thefollower guide 1521 to rotate in the second direction relative to thebarrel cam cylinder 1520 (that is, toward the first relativerotation-inhibiting position) and inhibits rotation of the followerguide 1521 relative to the barrel cam cylinder 1520 in the firstdirection.

In some embodiments and as shown in FIGS. 15J and 15K, the relativerotation-inhibiting mechanism 1575 may include a longitudinallyextending tab (or arm) 1577 (see also FIGS. 15C and 15H) carried by thefollower guide 1521 and a semi-annular flange 1579 (see also FIGS. 15Cand D) carried by the barrel cam cylinder 1520. FIG. 15J illustratessuch an embodiment of the relative rotation-inhibiting mechanism 1575 inthe first relative rotation-inhibiting position (the arm 1577 engages afirst side of the semi-annular flange 1579), and FIG. 15K illustratessuch an embodiment of the relative rotation-inhibiting mechanism 1575 inthe second relative rotation-inhibiting position (the arm 1577 engages asecond side of the semi-annular flange 1579).

In some embodiments, the relative rotation-inhibiting mechanism 1575 maytake other forms. For example, the mechanism 1575 may include one ormore magnets that hold the follower guide 1521 in the first and secondrelative rotation-inhibiting positions.

Referring to FIG. 15L, an exemplary spring assembly 1512 is depicted.The spring assembly 1512 includes a constant force spring 1572 and aspool 1574. One end of the constant force spring 1572 is connected tothe spool 1574, and the other end of the constant force spring 1572 isconnected to the post 1540 extending from the trigger 1508. As aclinician pulls the trigger 1508 proximally, the sliders 1532, 1536travel and slide in the grooves within the handle frame 1504, therebypreventing the trigger 1508 from moving vertically within the handleassembly 1208 and only allowing the trigger 1508 to move along thelongitudinal axis of the surgical device 1206 from its distal end towardits proximal end and/or vice versa. As the trigger 1508 movesproximally, the constant force spring 1572 uncoils, thereby creatingtension and a distally directed force. Accordingly, when the trigger1508 is released by the clinician, the constant force spring 1572recoils and pulls the trigger 1508 back towards its original and mostdistal position.

Referring to FIG. 16, there is depicted an elevation view of anembodiment of an assembled sheath assembly 1212 of the presentdisclosure. The sheath assembly 1212 includes an inner sheath assemblyand an outer sheath assembly. Referring to FIG. 16A, which illustratesan exploded view of the distal end of the sheath assembly 1212, andreferring to FIG. 16B, which is an exploded illustration of the proximalend and central portion of the sheath assembly 1212, the sheath assembly1212 may include may include some or all of the following components: anouter band 1636; a guide pin 1640; a cutting tip 1632; a flexible innersheath 1620; a flexible outer sheath 1624; an outer jacket 1628; aninner key 1612; an outer key 1608; and a rigid inner tube 1616.

Referring to FIG. 17A, there is depicted an embodiment of the outersheath assembly 1602 of the present disclosure. The outer sheathassembly 1602 includes an outer band 1636 located at and attached to thedistal end of an elongated flexible outer sheath 1624, and an outer key1608 located at and attached to the proximal end of the flexible outersheath 1624. The outer band 1636 may be attached to the distal end of aflexible outer sheath 1624 via a weld, an adhesive, a press-fittingtechnique, an interlock such as a barbed joint or other known means ofattachment. All such attachment techniques within the knowledge of oneskilled in the art are considered within the scope of this disclosure.Similarly, the outer key 1608 may be attached to the proximal end of theflexible outer sheath 1624 via a weld, an adhesive, a press-fittingtechnique, interlock such as a barbed joint, or other known means ofattachment. Although it is not shown on FIG. 17A, the outer sheathassembly 1602 may also include a flexible outer jacket 1628 (see FIG.16A) that covers the outer sheath 1624 and abuts the outer band 1636,thereby providing the outer sheath assembly 1602 with a relativelysmooth, continuous and uninterrupted exterior profile. The flexiblejacket also contains the egress of blood from the system.

Referring to FIG. 17B, there is depicted an embodiment of the innersheath assembly 1604 of the present disclosure. The inner sheathassembly 1604 includes a cutting tip 1632, a flexible inner sheath 1620,an inner key 1612, and a rigid inner tube 1616. The proximal end of thecutting tip 1632 is attached to the distal end of a flexible innersheath 1620; the distal end of an inner tube 1616 is attached to theproximal end of the flexible inner sheath 1620; and an inner key 1612 isattached to the proximal end of the inner tube 1616. The means ofattaching these components may include a weld, an adhesive, apress-fitting technique, or other known means of attachment. As will bediscussed below, the guide pin 1640 couples the outer band 1636 with thecutting tip 1632, and the guide pin 1640 may be includes with either theinner sheath assembly 1604 or the outer sheath assembly 1602.

It may be preferable for a portion of either the inner sheath 1620and/or the outer sheath 1624 to be rigid and a portion of the outersheath to be flexible. Both the rigid portion and the flexible portionmay be constructed of materials suitable for insertion into the humanbody. For example, the rigid portion may be constructed of stainlesssteel, and the flexible portion may be constructed of a flexible polymersuch as polytetrafluoroethylene or thermoplastic elastomers. Assumingthat both a rigid portion and a flexible portion are used, they willform a unitary inner sheath and/or outer sheath. As depicted in FIG.17B, the rigid inner tube 1616 is not only attached to the inner key1612, the rigid tube 1616 also is inserted through the inner key 1612and extends from both the proximal end and distal end of the inner key1612. The attachment and extension of the rigid tube 1616 to the innerkey 1612 allows for an increased amount of torque that can betransferred from the barrel cam to the rigid tube 1616 via the inner key1612 and eventually to the cutting tip 1632 via the inner sheathassembly 1604. The extension of the rigid tube through the handleprovides an access point for introduction of other medical devices. Theextension also provides a means of controlling blood egress after thelead has been extracted.

It may be preferable that at least a portion of the outer sheath 1624and the inner sheath 1620 be generally flexible in order to accept,accommodate and navigate the patient's vasculature system. In additionto being flexible, the inner sheath 1620 may also have a high degree ofstiffness in order to receive the torque transferred from the barrel camcylinder/inner key and transfer sufficient torque to the cutting tip1632 discussed in more detail below. The inner sheath 1620 (and/or theouter sheath 1624) may be formed of a polymer extrusion, braidedreinforced polymer extrusion, coils, bi-coils, tri-coils, laser cutmetal tubing and any combination of the above. The inner sheath (and/orthe outer sheath 1624) may be a unitary structure comprised of multipleportions.

Referring to FIG. 18, there is depicted a cross-sectional view of anembodiment of the sheath assembly 1212 comprising the inner sheathassembly 1604 located within the outer sheath assembly 1602. Referringto FIG. 18C, there is depicted an enlarged view of the inner key 1612 ofthe inner sheath assembly 1604 located within the outer key 1608 of theouter sheath assembly 1602. As discussed above, the exterior of theinner key 1612 is designed to mate with lumen 1556 of the distal end ofthe barrel cam cylinder 1520. Accordingly, the cross section of theexterior of proximal end of the inner key 1612 will have a profilecomplimentary to the distal end of the lumen 1556 within the barrel camcylinder 1520. For example, assuming the cross section of the distal end1552 of the lumen 1556 of the barrel cam cylinder 1520 is non-circularand has two chamfered sides, wherein one chamfered side is not offset,and the other chamfered side is offset (e.g., about 8 degrees), then theexterior of the proximal end of the inner key 1612 will also have anon-circular profile with two chamfered sides, wherein one chamferedside is not offset, and the other chamfered side is offset (e.g., about8 degrees). The inner key 1612 and outer key 1608 provide means forrotationally coupling. The inner key 1612 is a means for rotationallycoupling the inner sheath assembly 1604 to the barrel cam, and the outerkey is a means for rotationally coupling the outer shaft assembly to thehandle. The inner key 1612 and outer key 1608 provide journal bearingfor the other key.

As further illustrated in FIG. 18C, the inner key 1612 is able to rotatefreely within the outer key 1608 due, at least in part, to the distalend of the exterior of the inner key 1612 having a circular crosssection that mates with a circular cross section of the proximal end ofa lumen within the outer key 1608. Additionally, because the inner key1612 and outer key 1608 are loosely coupled, the inner key 1612 andouter key 1608 are able to move longitudinally with respect to oneanother. For instance, supposing the outer key 1608 is fixed such thatit neither rotates nor moves longitudinally, the inner key 1612 is ableto both rotate and travel longitudinally within the outer key 1608.Accordingly, as the barrel cam cylinder 1520 rotates, the inner key 1612will rotate within the outer key 1608, and the inner sheath assembly1604 will rotate within the outer sheath assembly 1602, including therotation of the cutting tip 1632 within the outer band 1636. And the camslot profile in the cutting tip 1632 controls the longitudinal movementof the inner sheath assembly 1604 within the outer sheath assembly 1602,including the longitudinal movement of the inner key 1612 relative tothe outer key 1608 and the longitudinal movement of the cutting tip 1632relative to the outer band 1636.

Continuing to refer to FIG. 18C, the lumen within the outer key 1608 islarger toward its proximal end and smaller toward its distal end becausethere is a step down or an abutment in the lumen as it progresses fromthe proximal end to the distal end. Due to the transition from a largerlumen to a smaller lumen within the outer key 1608, there is depicted anadjustable gap 1610 between the distal end of the inner key 1612 and theabutment within the distal end of the larger lumen in the outer key1608. This gap increases, decreases and/or remains the same according tothe cam slot profile of the cutting tip 1632. The abutment in the outerkey 1608 insures that the inner key 1612 will only travel a limitedlongitudinal distance within the outer key 1608, thereby limiting theinner sheath assembly 1604 potential longitudinal movement within theouter sheath assembly 1602, including limiting the longitudinal movementof the cutting tip 1632 relative to the outer band 1636 in the distaldirection.

Referring to FIG. 18A, there is depicted an enlarged cross-sectionalview of the distal end of the sheath assembly 1212 with the inner sheathassembly 1604 coupled with the outer sheath assembly 1602 via guide pin1640, wherein the blade 1822 of the cutting tip 1632 is in a retractedposition and located within the outer sheath assembly 1602. As discussedabove, the distal end of the outer sheath assembly 1602 includes anouter band 1636, which may be constructed of a biocompatible metal, suchas stainless steel, and polished so that it is generally smooth andevenly rounded at its most distal point, thereby allowing it to act as adilator when pressed and forced against tissue. The distal end 1822 ofcutting tip 1632 includes a cutting surface capable of cutting tissue.The inner sheath assembly 1604 is coupled to the outer sheath assembly1602 through the cutting tip 1632 and the outer band 1636, respectively,via guide pin 1640. One end of the guide pin 1640 is fixed within theouter band 1636, and the other end of the guide pin 1640 is locatedwithin the cam slot 1814 of the cutting tip 1632. As the inner sheath1620 rotates, upon actuation of the trigger assembly discussed above,the cutting tip 1632 also rotates because the inner sheath 1620 isfixedly attached to the cutting tip 1632. As the cutting tip 1632rotates, the cutting tip 1632 may also extend distally in the directionof the arrow (→) according to the profile of the cam slot 1814 asdepicted in FIG. 18A′. As the cutting tip 1632 extends distally androtates, the guide pin 1640 and the outer sheath assembly 1602,particularly the outer band 1636, remain stationary. Thus, as thecutting tip 1632 extends distally (and potentially retracts proximallyaccording to the cam slot profile) and rotates, the cutting surface atthe distal end 1822 of the cutting tip 1632 is able to perform a slicingaction against the tissue and cut it.

Again, FIG. 18A depicts the cutting tip 1632 within a retracted (andpotentially un-actuated) position because the cutting tip 1632 is in aproximal position. Stated differently, the distal end 1822 of thecutting tip 1632 of FIG. 18A is located within the interior of the outersheath assembly 1602, particularly the outer band 1636, and does notextend beyond the distal end of the outer band 1636. With reference toFIG. 18A′, the cutting tip 1632 is depicted in an extended (andactuated) position because the cutting tip 1632 is extending beyond thedistal end of the outer sheath assembly 1602 and the outer band 1636.

FIG. 14 depicts the distal portion of the flexible outer sheath andflexible inner sheath surrounding a lead 330 within a patient's vein 334with the cutting tip 1632 in its extended position. The circumferentialnature of the cutting surface (e.g., notched blade) at the distal end ofthe cutting tip 1632 causes the surgical device to act as a coringdevice, thereby cutting tissue 338 either partially (i.e., less than 360degrees) or completely (i.e., 360 degrees) around the lead or implantedobject being extracted. The amount of tissue that the cutting surfacecuts depends upon the size, shape and configuration of the lead, as wellas the diameter and thickness of the circular cutting blade. Forexample, if the diameter of the circular cutting surface issubstantially greater than the diameter of the lead, then the cuttingsurface will cut and core more tissue in comparison to a cutting surfacehaving a smaller diameter.

Although the inner sheath and outer sheath are coupled to one anothervia the cutting tip, the outer band, and the guide pin, the inner sheathassembly and outer sheath assembly may be coupled to one another inother ways. Stated differently, those of skill in the art willunderstand how to make and use the disclosed aspects, embodiments,and/or configurations after understanding the present disclosure tocouple the sheaths in a manner to allow a cutting surface to extend androtate beyond the distal end of the outer sheath. All suchconfigurations within the knowledge of one skilled in the art areconsidered within the scope of this disclosure.

With reference to FIGS. 19A, 19B and 19C, an exemplary outer band 1636is depicted. The outer band 1636 may be a sleeve in the general shape ofa hollow cylinder. Although the exterior of the outer band 1636 isnon-uniform, it may be uniform. The interior of the outer band 1636 isnon-uniform. For example, the interior of the outer band 1636 includesan abutment 1916 to prevent the cutting tip (not shown in FIGS. 19A, 19Band 19C) from traveling further from the proximal end 1912 to the distalend 1908 within the outer band 1636. The outer band 1636 also includes ahole 1904 for receipt and possible attachment of a guide pin (not shownin FIGS. 19A, 19B and 19C) which protrudes radially inward. As discussedin more detail above, the guide pin engages the cam slot of the cuttingtip. The size, shape and configuration of the outer band 1636 may differdepending upon how it is attached to the flexible outer sheath. Asdiscussed above, the outer sheath may be stationary. If so, the outerband 1636 and the guide pin remain stationary as the cutting tip moves(e.g., rotates and travel longitudinally) relative thereto. The outerband may also contain a journal bearing surface to align the cuttingblade during actuation and provide a surface to disengage the tissue atthe retraction of the cutting blade within the device.

With reference to FIGS. 20A, 20B, 20C and 20D, an exemplary cutting tip1632 is depicted. The cutting tip 1632 has a generally hollowcylindrical shape. The cutting tip 1632 comprises a proximal portion2024, an intermediate portion 2028, and a distal portion 2032. Theoutside diameter of the proximal portion 2024 is sized to allow it to beinserted to and/or engage (or otherwise attached to) the interiordiameter of the inner flexible sheath (not shown). The distal end ofcutting tip 1632 comprises a cutting surface 2012 having a serrated,sharp blade profile. The intermediate portion 2028 comprises a channel(or cam slot) 2016 cut within its exterior surface. As the innerflexible sheath rotates and moves within the outer sheath—from itsproximal end to distal end—the outer sheath and pin may remainstationary. If so, the inner sheath (not shown), which is connected tocutting tip 1632, forces the cutting tip 1632 to rotate. The cam slot2016 engages the guide pin, and the shape and profile of the cam slot2016 controls the rate and distance with which the cutting tip 1632travels longitudinally. That is, the configuration of the cam slot 2016controls the cutting tip's direction and amount of longitudinal travel,such as moving distally toward an extended position and/or proximallytoward a retracted position, while the cutting tip rotates in either aclockwise or counter-clockwise direction.

Referring again to FIGS. 20A, 20B, 20C and 20D, the cutting tip 1632 mayalso comprise a step up 2020 such that the diameter of the intermediateportion 2028 is greater than the distal portion 2032. As the cutting tip1632 rotates, and the cutting surface 2012 extends beyond the distal endof the outer band into an extended position, the step up 2020 of thecutting tip 1632 contacts the abutment of the outer band, therebylimiting the distance that the cutting tip 1632 may travel and/or mayprevent the cutting tip 1632 from exiting or extending beyond the distaltip of the outer sheath assembly, particularly the outer band, in theevent that the pin is sheared.

The profile of the cam slot in the cutting tip may have variousconfigurations, such as those disclosed in U.S. patent application Ser.No. 13/834,405 filed Mar. 15, 2013 and entitled Retractable Blade ForLead Removal Device, which is hereby incorporated herein by reference inits entirety for all that it teaches and for all purposes. For example,the cam slot may have a substantially linear profile, a substantiallysinusoidal profile, or a combination of individual and/or multiplelinear and non-linear profiles. Additionally, the cam slot may have anopen and continuous configuration, thereby allowing the cutting tip tocontinuously rotate, or the cam slot may have a closed and discontinuousconfiguration such that when the cutting tip reaches its fully extendedposition, the trigger assembly must be released or reversed so that thecutting tip returns to initially retracted position before beingre-actuated. For instance, the cam slot 2016 in FIG. 20A isdiscontinuous because the cam slot does not travel around the entirecircumference of the exterior of the cutting tip 1632. In someembodiments and as shown in FIGS. 21 and 22A-22C, the cam slot 2016 maybe symmetric over a longitudinally-extending plane. Although certainfigures in this disclosure only illustrate either the open or closed camslot configuration, either configuration may be used with any of theinner cam embodiments disclosed and/or discussed herein and areconsidered within the scope of this disclosure. Furthermore, varioustypes of cams, such as a partial lobe cam (which includes a cam slotsurrounding less than 360 degrees of the circumference of the exteriorsurface of the cutting tip), a single lobe cam (which includes a camslot surrounding 360 degrees of the circumference of the exteriorsurface of the cutting tip), double lobe cams (which includes a cam slotsurrounding 720 degrees of the circumference of the exterior surface ofthe cutting tip) and/or other multiple lobe cams.

The distal end of cutting tip 1632 may comprise a cutting surface 2012having different blade profiles, such as those disclosed in U.S. patentapplication Ser. No. 13/834,405 filed Mar. 15, 2013 and entitledRetractable Blade For Lead Removal Device, which is hereby incorporatedherein by reference in its entirety for all that it teaches and for allpurposes. For example, the plane of the cutting surface 2012 of thedistal end of the cutting tip depicted in the figures of this disclosureis parallel to the plane of the proximal end of the cutting tip. Theplane of the cutting surface, however, may be offset (0 degrees to 90degrees) from the plane of the proximal end of the cutting tip. Also, asdiscussed above, the profile of the cutting surface 2012 in FIGS.10A-10D has a plurality of serrations. The profile of the cuttingsurface 2012 need not be serrated and may comprise other configurations,such as a constant and/or smooth sharp profile. The profile of thecutting surface 2012 in FIGS. 20A-20D has a plurality of six (6)serrations. However, it may be preferable to have less than or more thansix (6) serrations. It may also be preferable to have between five (5)and seven (7) serrations, or between four (4) and eight (8) serrations,or between six (6) and ten (10) serrations.

Although the cutting surface 2012 illustrates a certain number ofserrations, FIGS. 20A-20D are not intended to represent the only numberand type of serrations that may be included in a serrated cuttingsurface. Depending upon the size of the surgical device, including thesheaths, and cutting tip, those of skill in the art will understand howto make and use the disclosed aspects, embodiments, and/orconfigurations after understanding the present disclosure to adjust thenumber, size and configurations of the serrations. All suchconfigurations within the knowledge of one skilled in the art areconsidered within the scope of this disclosure. Furthermore, theserrations may comprise a myriad of different shapes and configurations,including but not limited to any variation of a square, rectangle,rhombus, parallelogram, trapezoid, triangle, circle, ellipse, kite, etc.

FIG. 21 depicts two-dimensional illustrations of the profile of the camslot 2016 for the cutting tip 1632, the profile of the cam slot 1544 forthe barrel cam cylinder 1520, and the profile of the aperture 1565 ofthe follower guide 1521. FIGS. 22A-22C depict the how actuation of thetrigger 1508, and the resulting movement of the trigger pin 1528,results in rotational movement of the barrel cam cylinder 1520, thefollower guide 1521, and the cutting tip 1632, and translation movementof the cutting tip 1632. In these figures, a horizontal axis for theprofiles of the slots 2016 and 1544 is the degree(s) of rotation of thecutting tip 1632 and the barrel cam cylinder 1520. For example, assumingthat the profile of the cam slot in the cutting tip 1632 isdiscontinuous, as depicted in FIG. 20A, the cutting tip 1632 will rotateless than 360 degrees. It may be preferable for the cutting tip 1632 torotate between 5 and 355 degrees, 180 degrees and 355 degrees, 210degrees and 325 degrees, 240 degrees and 295 degrees, or 270 degrees and275 degrees. It may also be preferable for the cutting tip 1632 rotateabout 180, 185, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245,250, 255, 260, 265, 270, 275, 280, 285, 290, 300, 305, 310, 315, 320,325, 330, 335, 340, 345, 350 or 355 degrees. A vertical axis for theprofile of the cam slot 2016 for the cutting tip 1632 is the amount oflongitudinal displacement, if any, of the cutting tip 1632. The verticalaxis for the profile of the cam slot 1544 for the barrel cam cylinder1520 is the amount of longitudinal displacement of the trigger assembly(and trigger pin 1528).

In FIGS. 22A-22C, the aperture 1565 of the follower guide 1521 is shownas a dashed line and is overlaid on the profile of the cam slot 1544 forthe barrel cam cylinder 1520 to illustrate the rotational position ofthe aperture 1565 relative to the cam slot 1544. As shown in FIGS.22A-22C and explained in further detail below, the rotational positionof the aperture 1565 changes relative to the cam slot 1544 duringactuation of the trigger 1508.

Generally, an initial, or first, actuation of the trigger 1508 (that is,pulling the trigger 1508 as far as permitted by the handle assembly andthen releasing the trigger 1508 so that it returns to its home position)results in about a 254 degree rotational displacement of the cutting tip1632 and the barrel cam cylinder 1520 in one direction—clockwise whenlooking from the handle to the tip. The first actuation also extends thecutting tip 1632 from the outer band 1636 and then returns the cuttingtip 1632 to the sheathed position as the cutting tip 1632 rotates. Asubsequent, or second, actuation of the trigger 1508 results in about a254 degree rotational displacement of the cutting tip 1632 and thebarrel cam cylinder 1520 in the opposite direction—counter-clockwisewhen looking from the handle to the tip. The second actuation alsoextends the cutting tip 1632 from the outer band 1636 and then returnsthe cutting tip 1632 to the sheathed position as the cutting tip 1632rotates. Additional “odd” actuations (that is, a third actuation, afifth actuation, and so on) cause the same device motions as the firstactuation of the trigger 1508, and additional “even” actuations (thatis, a fourth actuation, a sixth actuation, and so on) cause the samedevice motions as the second actuation of the trigger 1508.

The following discussion more specifically explains the interactionbetween the rotation of the barrel cam cylinder 1520, the rotation ofthe follower guide 1521, the rotation of the cutting tip 1632, thelongitudinal movement of the handle (via the position of the trigger pin1528), and the longitudinal movement of the cutting tip 1632.

First and referring specifically to FIGS. 22A, 23A, 23B, and 23C, thefollowing is a description of the positions BC1′-BC3′ of the trigger pin1528 within the cam slot 1544 of the barrel cam cylinder 1520. In thesepositions, the follower guide 1521 is in the first relativerotation-inhibiting position, and the follower guide 1521 rotatestogether with the barrel cam cylinder 1520.

-   -   BC1′—The trigger pin 1528 is at a first home position within the        cam slot of the barrel cam cylinder 1520. The trigger 1508 of        the trigger assembly is also at its home position.    -   BC2′—The trigger pin 1528 has moved longitudinally in a proximal        direction, thereby causing the barrel cam cylinder 1520 to        rotate in a clockwise direction. The trigger pin 1528 engages        the first diagonally-extending wall 1567 of the aperture 1565 of        the follower guide 1521.    -   BC3′—The trigger pin 1528 has moved longitudinally further in        the proximal direction, thereby causing the barrel cam cylinder        1520 to rotate further in the clockwise direction. The trigger        pin 1528 engages the first longitudinally-extending wall 1571 of        the aperture 1565 of the follower guide 1521.

The positions BC1′-BC3′ of the trigger pin 1528 within the cam slot 1544of the barrel cam cylinder 1520 correspond to positions CT1′-CT3′ of theguide pin 1640 within the cam slot of the cutting tip 1632. Thefollowing is a description of the positions CT1′-CT3′ of the guide pin1640 within the cam slot of the cutting tip 1632.

-   -   CT1′—The guide pin 1640 is at a first home position within the        cam slot 2016 of the cutting tip 1632, and the cutting tip 1632        is in a retracted position within the outer sheath assembly 1602        (including the outer band 1636).    -   CT2′—The cutting tip 1632 has rotated in a clockwise direction        over the guide pin 1640 within the cam slot 2016 for about half        of its predetermined rotation. The cutting tip 1632 may be in        its most extended position outside the outer sheath assembly        1602.    -   CT3′—The cutting tip 1632 has rotated further in the clockwise        direction over the guide pin 1640 within the cam slot 2016. The        cutting tip 1632 may be in an intermediate position between the        extended position and the retracted position within the outer        sheath assembly 1602, or the cutting tip 1632 may be in the        retracted position within the outer sheath assembly 1602.

By beginning a first actuation of the trigger 1508 as described above,the trigger pin 1528 moves from its first home position BC1′ and intothe intersection 1545 of the cam slot 1544 of the barrel cam cylinder1520 (position BC2′). This action causes the barrel cam cylinder 1520and the cutting tip 1632 to rotate in a clockwise direction by about 127degrees. In position BC2′, the trigger pin 1528 engages the firstdiagonally-extending wall 1567 of the aperture 1565 of the followerguide 1521 to ensure that the trigger pin 1528 travels straight throughthe intersection 1545 of the cam slot 1544 of the barrel cam cylinder1520. Stated another way, the trigger pin 1528 travels from the firstleg 1547 of the cam slot 1544 to the second leg 1549 of the cam slot1544. Stated yet another way, the follower guide 1521 ensures that thattrigger pin 1528 traverses a first slot portion defined by the first leg1547 and the second leg 1549. This ensures that the barrel cam cylinder1520 continues to rotate in a clockwise direction. Engagement of thetrigger pin 1528 against the wall of the aperture 1565 of the followerguide 1521 tends to rotate the follower guide 1521 in a clockwisedirection relative to the barrel cam cylinder 1520. However, such motionis inhibited by the relative rotation-inhibiting mechanism 1575 in thefirst relative rotation-inhibiting position.

By continuing the first actuation of the trigger 1508, the trigger 1508pin moves from position BC2′ to position BC3′. This action causes thebarrel cam cylinder 1520 and the cutting tip 1632 to rotate in theclockwise direction by about 50 degrees. In position BC3′, the triggerpin 1528 engages the first longitudinally-extending wall 1571 of theaperture 1565 of the follower guide 1521. As described in further detailbelow, movement of the trigger pin 1528 past position BC3′ rotates thefollower guide 1521 in a counter-clockwise direction relative to thebarrel cam cylinder 1520.

Referring now to FIGS. 22B and 23D, the following is a description ofthe positions BC4′-BC6′ of the trigger pin 1528 within the cam slot 1544of the barrel cam cylinder 1520. In these positions, the follower guide1521 is in the second relative rotation-inhibiting position, and thefollower guide 1521 rotates together with the barrel cam cylinder 1520.

-   -   BC4′—The trigger pin 1528 has moved about its entire        longitudinal movement in a proximal direction and the barrel cam        cylinder 1520 has completed its rotation in a clockwise        direction. The trigger pin 1528 has rotated the follower guide        1521 to the second relative rotation-inhibiting position.    -   BC5′—The trigger pin 1528 has moved longitudinally in a distal        direction. The barrel cam cylinder 1520 has remained stationary.    -   BC6′—The trigger pin 1528 has moved longitudinally further in        the distal direction. The trigger pin 1528 is at a second home        position within the cam slot of the barrel cam cylinder 1520.        The trigger 1508 of the trigger assembly is also at its home        position.

The positions BC4′-BC6′ of the trigger pin 1528 within the cam slot ofthe barrel cam cylinder 1520 correspond to positions CT4′-CT6′ of theguide pin 1640 within the cam slot of the cutting tip 1632. Thefollowing is a description of the positions CT4′-CT6′ of the guide pin1640 within the cam slot of the cutting tip 1632.

-   -   CT4′—The cutting tip 1632 has completed its rotation in a        clockwise direction over the guide pin 1640 within the cam slot        2016. The cutting tip 1632 is in its most retracted position        within the outer sheath assembly 1602.    -   CT5′—(Not shown) the cutting tip 1632 has not moved relative to        position CT4′.    -   CT6′—The guide pin 1640 is at a second home position within the        cam slot 2016 of the cutting tip 1632, and the cutting tip 1632        is in a retracted position within the outer sheath assembly 1602        (including the outer band 1636).

By continuing the first actuation of the trigger 1508, the trigger pin1528 moves from position BC3′ (FIG. 22A) to position BC4′. This actioncauses the barrel cam cylinder 1520 and the cutting tip 1632 to rotatein the clockwise direction by about 110 degrees. This action also causesthe trigger pin 1528 to rotate the follower guide 1521 in acounter-clockwise direction by about 110 degrees relative to the barrelcam cylinder 1520. That is, the follower guide 1521 rotates from thefirst relative rotation-inhibiting position to the second relativerotation-inhibiting position. In the second relative rotation-inhibitingposition, the follower guide 1521 is positioned to ensure that thetrigger pin 1528 subsequently crosses its previous path and travelsstraight through the intersection 1545 of the cam slot 1544 of thebarrel cam cylinder 1520.

After the trigger pin 1528 reaches position BC4′, the trigger 1508 ismoved in a distal direction (for example, by releasing the trigger1508). This action causes the trigger pin 1528 to move from positionBC4′ to position BC5′ and then position BC6′. When the trigger pin 1528moves from position BC5′ to position BC6′, the barrel cam cylinder 1520and the cutting tip 1632 rotate in the counter-clockwise direction byabout 33 degrees. As such, the barrel cam cylinder 1520 and the cuttingtip 1632 are rotationally displaced by about 254 degrees in theclockwise direction as the trigger pin 1528 moves from position BC1′ toposition BC6′. The trigger pin 1528 remains at position BC6′, the secondhome position thereof, until the clinician begins a second actuation ofthe trigger 1508.

Referring now to FIGS. 22B, 23E, and 23F, the following is a descriptionof the positions BC7′-BC8′ of the trigger pin 1528 within the cam slot1544 of the barrel cam cylinder 1520. In these positions, the followerguide 1521 is in the second relative rotation-inhibiting position, andthe follower guide 1521 rotates together with the barrel cam cylinder1520.

-   -   BC7′—The trigger pin 1528 has moved longitudinally in a proximal        direction, thereby causing the barrel cam cylinder 1520 to        rotate in a counter-clockwise direction. The trigger pin 1528        engages the second diagonally-extending wall 1569 of the        aperture 1565 of the follower guide 1521.    -   BC8′—The trigger pin 1528 has moved longitudinally further in        the proximal direction, thereby causing the barrel cam cylinder        1520 to rotate further in the counter-clockwise direction. The        trigger pin 1528 engages the second longitudinally-extending        wall 1573 of the aperture 1565 of the follower guide 1521.

The positions BC7′-BC8′ of the trigger pin 1528 within the cam slot ofthe barrel cam cylinder 1520 correspond to positions CT7′-CT8′ of theguide pin 1640 within the cam slot of the cutting tip 1632. Thefollowing is a description of the positions CT7′-CT8′ of the guide pin1640 within the cam slot of the cutting tip 1632.

-   -   CT7′—The cutting tip 1632 has rotated in a counter-clockwise        direction over the guide pin 1640 within the cam slot 2016 for        about half of its predetermined rotation. The cutting tip 1632        may be in its most extended position outside the outer sheath        assembly 1602.    -   CT8′—The cutting tip 1632 has rotated further in the        counter-clockwise direction over the guide pin 1640 within the        cam slot 2016. The cutting tip 1632 may be in an intermediate        position between the extended position and the retracted        position within the outer sheath assembly 1602, or the cutting        tip 1632 may be in the retracted position within the outer        sheath assembly 1602.

By beginning a second actuation of the trigger 1508 as described above,the trigger pin 1528 moves from its second home position BC6′ and intothe intersection 1545 of the cam slot 1544 of the barrel cam cylinder1520 (position BC7′). This action causes the barrel cam cylinder 1520and the cutting tip 1632 to rotate in a counter-clockwise direction by127 degrees. In position BC7′, the trigger pin 1528 engages the seconddiagonally-extending wall 1569 of the aperture 1565 of the followerguide 1521 to ensure that the trigger pin 1528 travels straight throughthe intersection 1545 of the cam slot 1544 of the barrel cam cylinder1520. Stated another way, the trigger pin 1528 travels from the thirdleg 1551 of the cam slot 1544 to the fourth leg 1553 of the cam slot1544. Stated yet another way, the follower guide 1521 ensures that thattrigger pin 1528 traverses a second slot portion defined by the thirdleg 1551 and the fourth leg 1553. This ensures that the barrel camcylinder 1520 continues to rotate in a counter-clockwise direction.Engagement of the trigger pin 1528 against the wall of the aperture 1565of the follower guide 1521 tends to rotate the follower guide 1521 in acounter-clockwise direction relative to the barrel cam cylinder 1520.However, such motion is inhibited by the relative rotation-inhibitingmechanism 1575 in the second relative rotation-inhibiting position.

By continuing the second actuation of the trigger 1508, the trigger 1508pin moves from position BC7′ to position BC8′. This action causes thebarrel cam cylinder 1520 and the cutting tip 1632 to further rotate inthe counter-clockwise direction by 50 degrees. In position BC8′, thetrigger pin 1528 engages the second longitudinally-extending wall 1573of the aperture 1565 of the follower guide 1521. As described in furtherdetail below, movement of the trigger pin 1528 past position BC8′rotates the follower guide 1521 in a clockwise direction relative to thebarrel cam cylinder 1520.

Referring now to FIGS. 22C and 23A, the following is a description ofthe positions BC9′-BC10′ of the trigger pin 1528 within the cam slot ofthe barrel cam cylinder 1520. In these positions, the follower guide1521 is in the first relative rotation-inhibiting position, and thefollower guide 1521 rotates together with the barrel cam cylinder 1520.

-   -   BC9′—The trigger pin 1528 has moved about its entire        longitudinal movement in a proximal direction and the barrel cam        cylinder 1520 has completed its rotation in a counter-clockwise        direction. The trigger pin 1528 has rotated the follower guide        1521 back to the first relative rotation-inhibiting position.    -   BC10′—The trigger pin 1528 has moved longitudinally in a distal        direction. The barrel cam cylinder 1520 has remained stationary.

The positions BC9′-BC10′ of the trigger pin 1528 within the cam slot ofthe barrel cam cylinder 1520 correspond to positions CT9′-CT10′ of theguide pin 1640 within the cam slot of the cutting tip 1632. Thefollowing is a description of the positions CT9′-CT10′ of the guide pin1640 within the cam slot of the cutting tip 1632.

-   -   CT9′—The cutting tip 1632 has completed its rotation in a        counter-clockwise direction over the guide pin 1640 within the        cam slot 2016. The cutting tip 1632 is in its most retracted        position within the outer sheath assembly 1602.    -   CT10′—(Not shown) the cutting tip 1632 has not moved relative to        position CT9′.

By continuing the second actuation of the trigger 1508, the trigger pin1528 moves from position BC8′ (FIG. 22B) to position BC9′. This actioncauses the barrel cam cylinder 1520 and the cutting tip 1632 to furtherrotate in the counter-clockwise direction by 110 degrees. This actionalso causes the trigger pin 1528 to rotate the follower guide 1521 in aclockwise direction relative to the barrel cam cylinder 1520 by 100degrees. That is, the follower guide 1521 rotates from the secondrelative rotation-inhibiting position back to the first relativerotation-inhibiting position. In the first relative rotation-inhibitingposition, the follower guide 1521 is again positioned to ensure that thetrigger pin 1528 subsequently crosses its previous path and travelsstraight through the intersection 1545 of the cam slot 1544 of thebarrel cam cylinder 1520.

After the trigger pin 1528 reaches position BC9′, the trigger 1508 ismoved in a distal direction (for example, by releasing the trigger1508). This action causes the trigger pin 1528 to move from positionBC9′ to position BC10′ and then position BC1′. When the trigger pin 1528moves from position BC10′ to position BC1′, the barrel cam cylinder 1520and the cutting tip 1632 rotate in the clockwise direction by about 33degrees. As such, the barrel cam cylinder 1520 and the cutting tip 1632are rotationally displaced by about 254 degrees in the counter-clockwisedirection as the trigger pin 1528 moves from position BC6′ to positionBC1′.

The trigger pin 1528 remains at position BC1′, the first home positionthereof, until the clinician begins a third actuation of the trigger1508. As described above, additional “odd” actuations (that is, a thirdactuation, a fifth actuation, and so on) of the trigger 1508 cause thesame device motions as the first actuation of the trigger 1508, andadditional “even” actuations (that is, a fourth actuation, a sixthactuation, and so on) of the trigger 1508 cause the same device motionsas the second actuation of the trigger 1508.

Referring now to FIGS. 24-28, an exemplary barrel cam assembly 2419 isdepicted. The barrel cam assembly 2419 may be used with a surgicaldevice, such as the surgical device 1206 described above, in place ofthe barrel cam assembly 1519. The barrel cam assembly 2419 includes abarrel cam cylinder 2420 that rotatably carries a follower guide 2421.The barrel cam cylinder 2420 and the follower guide 2421 may have thesame features as any of the barrel cam cylinders and the followerguides, respectively, described herein (for example, the cam groove 1544and the follower aperture 1565, respectively), with the exception of therelative rotation-inhibiting mechanism.

The barrel cam assembly 2419 includes a relative rotation-inhibitingmechanism 2475 that inhibits some rotation of the follower guide 2421relative to the barrel cam cylinder 2420. Generally, the relativerotation-inhibiting mechanism 2475 permits the follower guide 2421 tomove from a first relative rotation-inhibiting position (referred to asthe “first locked position” for simplicity) to a second relativerotation-inhibiting position (referred to as the “first locked position”for simplicity) and vice versa. In the first locked position, themechanism 2475 initially inhibits the follower guide 2421 from rotatingin a first direction relative to the barrel cam cylinder 2420 (that is,toward the second locked position) and inhibits rotation of the followerguide 2421 in a second direction relative to the barrel cam cylinder2420. In the second locked position, the mechanism 2475 initiallyinhibits the follower guide 2421 from rotating in the second directionrelative to the barrel cam cylinder 2420 (that is, toward the firstlocked position) and inhibits rotation of the follower guide 2421 in thefirst direction relative to the barrel cam cylinder 2420.

The relative rotation-inhibiting mechanism 2475 includes aradially-outwardly projecting protrusion 2402 formed near the proximalend of the barrel cam cylinder 2420. The protrusion 2402 may be formedon the barrel cam cylinder 2420 in a machining process. The protrusion2402 includes a proximally-facing curved recess 2404. The protrusion2402 also includes a first transversely-facing engagement surface 2406and a second transversely-facing engagement surface 2408.

The relative rotation-inhibiting mechanism 2475 also includes a firstspring prong 2410, a second spring prong 2412 (see FIG. 25), a firsttransversely-facing engagement surface 2413, and a secondtransversely-facing engagement surface 2414 (see FIG. 25) formed nearthe proximal end of the follower guide 2421. The spring prongs 2410,2412 and the engagement surfaces 2413, 2414 may be formed on thefollower guide 2421 in a laser cutting process.

The first spring prong 2410 is cantilevered from the remainder of thefollower guide 2421 and extends partially about the circumference of thefollower guide 2421. The first spring prong 2410 includes a curved tip2418 that selectively engages the curved recess 2404 of the protrusion2402 to inhibit rotation of the follower guide 2421 relative to thebarrel cam cylinder 2420. This aspect is described in further detailbelow. In some embodiments, the curved tip 2418 has a radius of about0.040 inches and 0.015 inches of interference with the curved recess2404 of the protrusion 2402. Such dimensions facilitate both securementand slidable detachment of the first spring prong 2410 relative to theprotrusion 2402.

The second spring prong 2412 is cantilevered from the remainder of thefollower guide 2421. The second spring prong 2412 extends partiallyabout the circumference of the follower guide 2421 and faces in theopposite circumferential direction as the first spring prong 2410. Thesecond spring prong 2412 includes a curved tip 2422 that selectivelyengages the curved recess 2404 of the protrusion 2402 to inhibitrotation of the follower guide 2421 relative to the barrel cam cylinder2420. This aspect is described in further detail below. In someembodiments, the curved tip 2422 has a radius of about 0.040 inches and0.015 inches of interference with the curved recess 2404 of theprotrusion 2402. Such dimensions facilitate both securement and slidabledetachment of the second spring prong 2412 relative to the protrusion2402.

Interaction of the first and second spring prongs 2410, 2412 with theprotrusion 2402, and the resulting motion of the follower guide 2421relative to the barrel cam cylinder 2420, are described with referenceto the cam slot and aperture profiles illustrated in FIGS. 22A-22C.Referring first to FIG. 22A and upon a first actuation of the triggerassembly, the trigger pin initially moves from position BC1′ to BC3′. Asthe trigger pin moves in this manner, the follower guide 2421 rotatestogether with the barrel cam cylinder 2420 because the curved tip 2418of the first spring prong 2410 is engaged with the curved recess 2404 ofthe protrusion 2402. Stated another way, the first spring prong 2410engages the protrusion 2402 to initially hold the follower guide 2421 inthe first locked position relative to the barrel cam cylinder 2420.

Referring to FIG. 22B and by continuing the first actuation of thetrigger assembly, the trigger pin moves from position BC3′ to BC4′. Inposition BC3′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC4′, the trigger pin applies aforce to the follower guide 2421 that causes the curved tip 2418 of thefirst spring prong 2410 to slip over and disengage the curved recess2404 of the protrusion 2402. As a result, the follower guide 2421 is“unlocked” and rotates relative to the barrel cam cylinder 2420 as thetrigger pin moves from position BC3′ to BC4′. As the trigger pinapproaches position BC4′, the curved tip 2422 of the second spring prong2412 slips over and engages the curved recess 2404 of the protrusion2402. The follower guide 2421 thereby enters the second locked positionrelative to the barrel cam cylinder 2420.

When the user releases the trigger assembly, the trigger pin moves fromposition BC4′ to BC6′. As the trigger pin moves in this manner, thefollower guide 2421 rotates together with the barrel cam cylinder 2420because the curved tip 2422 of the second spring prong 2412 is engagedwith the curved recess 2404 of the protrusion 2402. Stated another way,the second spring prong 2412 engages the protrusion 2402 to hold thefollower guide 2421 in the second locked position relative to the barrelcam cylinder 2420 after the first actuation of the trigger assembly.

Still referring to FIG. 22B and upon a second actuation of the triggerassembly, the trigger pin initially moves from position BC6′ to BC8′. Asthe trigger pin moves in this manner, the follower guide 2421 rotatestogether with the barrel cam cylinder 2420 because the curved tip 2422of the second spring prong 2412 is engaged with the curved recess 2404of the protrusion 2402. Stated another way, the second spring prong 2412engages the protrusion 2402 to initially hold the follower guide 2421 inthe second locked position relative to the barrel cam cylinder 2420.

Referring to FIG. 22C and by continuing the second actuation of thetrigger assembly, the trigger pin moves from position BC8′ to BC9′. Inposition BC8′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC9′, the trigger pin applies aforce to the follower guide 2421 that causes the curved tip 2422 of thesecond spring prong 2412 to slip over and disengage the curved recess2404 of the protrusion 2402. As a result, the follower guide 2421 is“unlocked” and rotates relative to the barrel cam cylinder 2420 as thetrigger pin moves from position BC8′ to BC9′. As the trigger pinapproaches position BC9′, the curved tip 2418 of the first spring prong2410 slips over and engages the curved recess 2404 of the protrusion2402. The follower guide 2421 thereby returns to the first lockedposition relative to the barrel cam cylinder 2420.

When the user releases the trigger assembly, the trigger pin moves fromposition BC9′ to BC1′. As the trigger pin moves in this manner, thefollower guide 2421 rotates together with the barrel cam cylinder 2420because the curved tip 2418 of the first spring prong 2410 is engagedwith the curved recess 2404 of the protrusion 2402. Stated another way,the first spring prong 2410 engages the protrusion 2402 to hold thefollower guide 2421 in the first locked position relative to the barrelcam cylinder 2420 after the second actuation of the trigger assembly.

In addition and as shown in FIG. 24, the first engagement surface 2413of the follower guide 2421 engages the first engagement surface 2406 ofthe protrusion 2402 in the first locked position to inhibit the followerguide 2421 from rotating in a direction away from the second lockedposition. The second engagement surface 2414 of the follower guide 2421engages the second engagement surface 2408 of the protrusion 2402 in thesecond locked position to inhibit the follower guide 2421 from rotatingin a direction away from the first locked position.

Referring now to FIGS. 29-30, an exemplary barrel cam assembly 2919 isdepicted. The barrel cam assembly 2919 may be used with a surgicaldevice, such as the surgical device 1206 described above, in place ofthe barrel cam assembly 1519. The barrel cam assembly 2919 includes abarrel cam cylinder 2920 that rotatably carries a follower guide 2921.The barrel cam cylinder 2920 and the follower guide 2921 may have thesame features as any of the barrel cam cylinders and the followerguides, respectively, described herein (for example, the cam groove 1544and the follower aperture 1565, respectively), with the exception of therelative rotation-inhibiting mechanism.

The barrel cam assembly 2919 includes a relative rotation-inhibitingmechanism 2975 that inhibits some rotation of the follower guide 2921relative to the barrel cam cylinder 2920. Generally, the relativerotation-inhibiting mechanism 2975 permits the follower guide 2921 tomove from a first relative rotation-inhibiting position (referred to asthe “first locked position” for simplicity) to a second relativerotation-inhibiting position (referred to as the “first locked position”for simplicity) and vice versa. In the first locked position, themechanism 2975 initially inhibits the follower guide 2921 from rotatingin a first direction relative to the barrel cam cylinder 2920 (that is,toward the second locked position) and inhibits rotation of the followerguide 2921 in a second direction relative to the barrel cam cylinder2920. In the second locked position, the mechanism 2975 initiallyinhibits the follower guide 2921 from rotating in the second directionrelative to the barrel cam cylinder 2920 (that is, toward the firstlocked position) and inhibits rotation of the follower guide 2921 in thefirst direction relative to the barrel cam cylinder 2920.

The relative rotation-inhibiting mechanism 2975 includes aradially-outwardly projecting pin 2902 carried near the proximal end ofthe barrel cam cylinder 2920. The pin 2902 may be coupled to the barrelcam cylinder 2920 in various manners. For example, the pin 2902 may bepress fitted or adhered in a hole formed on the barrel cam cylinder2920. In some embodiments, the relative rotation-inhibiting mechanism2975 also includes a radially outwardly-facing curved recess 2904 formednear the proximal end of the barrel cam cylinder 2920. The curved recess2904 may be angularly offset from the pin 2902 about the longitudinalaxis of the barrel cam cylinder 2920.

The relative rotation-inhibiting mechanism 2975 also includes a springarm 2908, a first transversely-facing engagement surface 2913, and asecond transversely-facing engagement surface 2914 formed near theproximal end of the follower guide 2921.

The spring arm 2908 is cantilever from the remainder of the followerguide 2921 at a first end. At an opposite end, the spring arm 2908includes a radially inwardly-facing curved finger 2910. The finger 2910selectively engages the curved recess 2904 of the barrel cam cylinder2920 to inhibit rotation of the follower guide 2921 relative to thebarrel cam cylinder 2920. This aspect is described in further detailbelow.

Interaction of the spring arm 2908 with the barrel cam cylinder 2920,and the resulting motion of the follower guide 2921 relative to thebarrel cam cylinder 2920, are described with reference to the cam slotand aperture profiles illustrated in FIGS. 22A-22C. Referring first toFIG. 22A and upon a first actuation of the trigger assembly, the triggerpin initially moves from position BC1′ to BC3′. As the trigger pin movesin this manner, the follower guide 2921 rotates together with the barrelcam cylinder 2920 because the finger 2910 is engaged with the curvedrecess 2904 of the barrel cam cylinder 2920. Stated another way, thefinger 2910 engages the curved recess 2904 to initially hold thefollower guide 2921 in the first locked position relative to the barrelcam cylinder 2920.

Referring to FIG. 22B and by continuing the first actuation of thetrigger assembly, the trigger pin moves from position BC3′ to BC4′. Inposition BC3′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC4′, the trigger pin applies aforce to the follower guide 2921 that causes the finger 2910 to slipover and disengage the curved recess 2904 of the barrel cam cylinder2920. As a result, the follower guide 2921 is “unlocked” and rotatesrelative to the barrel cam cylinder 2920 as the trigger pin moves fromposition BC3′ to BC4′. The finger 2910 slips over and engages the outersurface of the barrel cam cylinder 2920 as the follower guide 2921rotates relative to the barrel cam cylinder 2920. As the trigger pinapproaches position BC4′, the finger 2910 remains engaged with thecurved recess 2904 of the barrel cam cylinder 2920. The follower guide2921 thereby enters the second locked position relative to the barrelcam cylinder 2920.

When the user releases the trigger assembly, the trigger pin moves fromposition BC4′ to BC6′. As the trigger pin moves in this manner, thefollower guide 2921 rotates together with the barrel cam cylinder 2920because the finger 2910 is engaged with the outer surface of the barrelcam cylinder 2920. Stated another way, the finger 2910 remains engagedwith the outer surface of the barrel cam cylinder 2920 to hold thefollower guide 2921 in the second locked position relative to the barrelcam cylinder 2920 after the first actuation of the trigger assembly.

Still referring to FIG. 22B and upon a second actuation of the triggerassembly, the trigger pin initially moves from position BC6′ to BC8′. Asthe trigger pin moves in this manner, the follower guide 2921 rotatestogether with the barrel cam cylinder 2920 due to frictional forcesbetween the finger 2910 and the outer surface of the barrel cam cylinder2920. Stated another way, the finger 2910 engages the outer surface ofthe barrel cam cylinder 2920 to initially hold the follower guide 2921in the second locked position relative to the barrel cam cylinder 2920.

Referring to FIG. 22C and by continuing the second actuation of thetrigger assembly, the trigger pin moves from position BC8′ to BC9′. Inposition BC8′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC9′, the trigger pin applies aforce to the follower guide 2921 that overcomes the frictional forcesbetween the finger 2910 and the outer surface of the barrel cam cylinder2920. As a result, the finger 2910 slips over the outer surface of thebarrel cam cylinder 2920, and the follower guide 2921 is “unlocked” androtates relative to the barrel cam cylinder 2920 as the trigger pinmoves from position BC8′ to BC9′. As the trigger pin approaches positionBC9′, the finger 2910 slips over and engages the curved recess 2904 ofbarrel cam cylinder 2920. The follower guide 2921 thereby returns to thefirst locked position relative to the barrel cam cylinder 2920.

When the user releases the trigger assembly, the trigger pin moves fromposition BC9′ to BC1′. As the trigger pin moves in this manner, thefollower guide 2921 rotates together with the barrel cam cylinder 2920because the finger 2910 is engaged with the curved recess 2904 of thebarrel cam cylinder 2920. Stated another way, the finger 2910 engagesthe protrusion 2902 to hold the follower guide 2921 in the first lockedposition relative to the barrel cam cylinder 2920 after the secondactuation of the trigger assembly.

In addition and as shown in FIG. 29, the first engagement surface 2913of the follower guide 2921 engages the pin 2902 of the barrel camcylinder 2920 in the first locked position to inhibit the follower guide2921 from rotating in a direction away from the second locked position.The second engagement surface 2914 of the follower guide 2921 engagesthe pin 2902 in the second locked position to inhibit the follower guide2921 from rotating in a direction away from the first locked position.

In some embodiments, the barrel cam cylinder 2920 includes a secondradially outwardly-facing curved recess (not shown) that receives thefinger 2910 in the second locked position of the follower guide 2921. Insome embodiments, the barrel cam cylinder 2920 lacks any radiallyoutwardly-facing curved recesses. Instead, the finger 2910 remains inengagement with the outer surface of the barrel cam cylinder 2920 in thefirst locked position, the second locked position, and the unlockedposition.

Referring now to FIG. 31, an exemplary barrel cam assembly 3119 isdepicted. The barrel cam assembly 3119 may be used with a surgicaldevice, such as the surgical device 1206 described above, in place ofthe barrel cam assembly 1519. The barrel cam assembly 3119 includes abarrel cam cylinder 3120 that rotatably carries a follower guide 3121.The barrel cam cylinder 3120 and the follower guide 3121 may have thesame features as any of the barrel cam cylinders and the followerguides, respectively, described herein (for example, the cam groove 1544and the follower aperture 1565, respectively), with the exception of therelative rotation-inhibiting mechanism.

The barrel cam assembly 3119 includes a relative rotation-inhibitingmechanism 3175 that inhibits some rotation of the follower guide 3121relative to the barrel cam cylinder 3120. Generally, the relativerotation-inhibiting mechanism 3175 permits the follower guide 3121 tomove from a first relative rotation-inhibiting position (referred to asthe “first locked position” for simplicity) to a second relativerotation-inhibiting position (referred to as the “first locked position”for simplicity) and vice versa. In the first locked position, themechanism 3175 initially inhibits the follower guide 3121 from rotatingin a first direction relative to the barrel cam cylinder 3120 (that is,toward the second locked position) and inhibits rotation of the followerguide 3121 in a second direction relative to the barrel cam cylinder3120. In the second locked position, the mechanism 3175 initiallyinhibits the follower guide 3121 from rotating in the second directionrelative to the barrel cam cylinder 3120 (that is, toward the firstlocked position) and inhibits rotation of the follower guide 3121 in thefirst direction relative to the barrel cam cylinder 3120.

The relative rotation-inhibiting mechanism 3175 includes aradially-outwardly projecting pin 3102 carried near the proximal end ofthe barrel cam cylinder 3120. The pin 3102 may be coupled to the barrelcam cylinder 3120 in various manners. For example, the pin 3102 may bepress fitted or adhered in a hole formed on the barrel cam cylinder3120.

The relative rotation-inhibiting mechanism 3175 also includes first andsecond spherical elements 3108 and 3110. The first and second sphericalelements 3108 and 3110 are fixedly received in cylindrical blind holesformed in the outer surface of the barrel cam cylinder 3120. The firstand second spherical elements 3108 and 3110 protrude from the holes toengage the inner surface of the follower guide 3121. As such, the firstand second spherical elements 3108 and 3110 facilitate frictionalengagement between the barrel cam cylinder 3120 and the follower guide3121.

In some embodiments, the first and second spherical elements 3108 and3110 are press fitted into the holes on the barrel cam cylinder 3120. Insome embodiments, the first and second spherical elements 3108 and 3110may be disposed near the proximal end and the distal end, respectively,of the barrel cam cylinder 3120. In some embodiments, the first andsecond spherical elements 3108 and 3110 are formed of steel,polyethylene, or the like. In some embodiments, the first and secondspherical elements 3108 and 3110 are similar to the rolling elements, orballs, of a ball bearing.

The relative rotation-inhibiting mechanism 3175 further includes a firsttransversely-facing engagement surface 3113 and a secondtransversely-facing engagement surface 3114 formed near the proximal endof the follower guide 3121.

In some embodiments, the relative rotation-inhibiting mechanism 3175further includes a through hole 3112 formed on the follower guide 3121.The through hole 3112 has a diameter that is smaller than the diameterof the first spherical element 3108. The through hole 3112 receives thefirst spherical element 3108 in the first locked position of thefollower guide 3121. Entry of the first spherical element 3108 in thethrough hole 3112 provides tactile feedback to the device user.

Interaction of the first and second spherical elements 3108 and 3110with the follower guide 3121, and the resulting motion of the followerguide 3121 relative to the barrel cam cylinder 3120, are described withreference to the cam slot and aperture profiles illustrated in FIGS.22A-22C. Referring first to FIG. 22A and upon a first actuation of thetrigger assembly, the trigger pin initially moves from position BC1′ toBC3′. As the trigger pin moves in this manner, the follower guide 3121rotates together with the barrel cam cylinder 3120 due to the frictionalforces between the first and second spherical elements 3108 and 3110 andthe follower guide 3121. Stated another way, the first and secondspherical elements 3108 and 3110 initially hold the follower guide 3121in the first locked position relative to the barrel cam cylinder 3120.

Referring to FIG. 22B and by continuing the first actuation of thetrigger assembly, the trigger pin moves from position BC3′ to BC4′. Inposition BC3′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC4′, the trigger pin applies aforce to the follower guide 3121 that overcomes the frictional forcesbetween the first and second spherical elements 3108 and 3110 and thefollower guide 3121. As a result, the first and second sphericalelements 3108 and 3110 slip against the follower guide 3121, and thefollower guide 3121 is “unlocked” and rotates relative to the barrel camcylinder 3120 as the trigger pin moves from position BC3′ to BC4′. Whenthe trigger pin reaches position BC4′, the trigger pin no longer appliesthe force to the follower guide 3121.

When the user releases the trigger assembly, the trigger pin moves fromposition BC4′ to BC6′. As the trigger pin moves in this manner, thefollower guide 3121 rotates together with the barrel cam cylinder 3120due to the frictional forces between the first and second sphericalelements 3108 and 3110 and the follower guide 3121. Stated another way,the first and second spherical elements 3108 and 3110 hold the followerguide 3121 in the second locked position relative to the barrel camcylinder 3120 after the first actuation of the trigger assembly.

Still referring to FIG. 22B and upon a second actuation of the triggerassembly, the trigger pin initially moves from position BC6′ to BC8′. Asthe trigger pin moves in this manner, the follower guide 3121 rotatestogether with the barrel cam cylinder 3120 due to the frictional forcesbetween the first and second spherical elements 3108 and 3110 and thefollower guide 3121. Stated another way, the first and second sphericalelements 3108 and 3110 initially hold the follower guide 3121 in thesecond locked position relative to the barrel cam cylinder 3120.

Referring to FIG. 22C and by continuing the second actuation of thetrigger assembly, the trigger pin moves from position BC8′ to BC9′. Inposition BC8′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC9′, the trigger pin applies aforce to the follower guide 3121 that overcomes the frictional forcesbetween the first and second spherical elements 3108 and 3110 and thefollower guide 3121. As a result, the first and second sphericalelements 3108 and 3110 slip against the follower guide 3121, and thefollower guide 3121 is “unlocked” and rotates relative to the barrel camcylinder 3120 as the trigger pin moves from position BC8′ to BC9′. Whenthe trigger pin reaches position BC9′, the trigger pin no longer appliesthe force to the follower guide 3121.

When the user releases the trigger assembly, the trigger pin moves fromposition BC9′ to BC1′. As the trigger pin moves in this manner, thefollower guide 3121 rotates together with the barrel cam cylinder 3120due to the frictional forces between the first and second sphericalelements 3108 and 3110 and the follower guide 3121. Stated another way,the first and second spherical elements 3108 and 3110 hold the followerguide 3121 in the first locked position relative to the barrel camcylinder 3120 after the second actuation of the trigger assembly.

In addition and as shown in FIG. 31, the first engagement surface 3113of the follower guide 3121 engages the pin 3102 of the barrel camcylinder 3120 in the first locked position to inhibit the follower guide3121 from rotating in a direction away from the second locked position.The second engagement surface 3114 of the follower guide 3121 engagesthe pin 3102 in the second locked position to inhibit the follower guide3121 from rotating in a direction away from the first locked position.

In some embodiments, the barrel cam assembly 3119 includes one sphericalelement, or three or more spherical elements. In some embodiments, oneor more of the spherical elements 3108 and/or 3110 are received inthrough holes formed on the follower guide 3121 in the first and/orsecond locked positions. Entry of the spherical elements in the throughholes provides tactile feedback to the device user.

Referring now to FIG. 32, an exemplary barrel cam assembly 3219 isdepicted. The barrel cam assembly 3219 may be used with a surgicaldevice, such as the surgical device 1206 described above, in place ofthe barrel cam assembly 1519. The barrel cam assembly 3219 includes abarrel cam cylinder 3220 that rotatably carries a follower guide 3221.The barrel cam cylinder 3220 and the follower guide 3221 may have thesame features as any of the barrel cam cylinders and the followerguides, respectively, described herein (for example, the cam groove 1544and the follower aperture 1565, respectively), with the exception of therelative rotation-inhibiting mechanism.

The barrel cam assembly 3219 includes a relative rotation-inhibitingmechanism 3275 that inhibits some rotation of the follower guide 3221relative to the barrel cam cylinder 3220. Generally, the relativerotation-inhibiting mechanism 3275 permits the follower guide 3221 tomove from a first relative rotation-inhibiting position (referred to asthe “first locked position” for simplicity) to a second relativerotation-inhibiting position (referred to as the “first locked position”for simplicity) and vice versa. In the first locked position, themechanism 3275 initially inhibits the follower guide 3221 from rotatingin a first direction relative to the barrel cam cylinder 3220 (that is,toward the second locked position) and inhibits rotation of the followerguide 3221 in a second direction relative to the barrel cam cylinder3220. In the second locked position, the mechanism 3275 initiallyinhibits the follower guide 3221 from rotating in the second directionrelative to the barrel cam cylinder 3220 (that is, toward the firstlocked position) and inhibits rotation of the follower guide 3221 in thefirst direction relative to the barrel cam cylinder 3220.

The relative rotation-inhibiting mechanism 3275 includes alongitudinally extending tab 3277 formed near the proximal end of thefollower guide 3221. The tab 3277 engages a semi-annular flange 3279formed near the proximal end of the barrel cam cylinder 3220. As shownin FIG. 31, the tab 3277 engages one side of the flange 3279 in thefirst locked position to inhibit the follower guide 3221 from rotatingin a direction away from the second locked position. The tab 3277engages the other side of the flange 3279 in the second locked positionto inhibit the follower guide 3221 from rotating in a direction awayfrom the first locked position.

The relative rotation-inhibiting mechanism 3275 also includes a frictionelement 3208 that is fixedly carried by the barrel cam cylinder 3220.The friction element 3208 engages the follower guide 3221 to providefrictional engagement between the barrel cam cylinder 3220 and thefollower guide 3221. In some embodiments, the friction element 3208 isformed by Teflon, polyethylene, nylon, or the like. In some embodiments,the friction element 3208 has a disk shape, a spring washer shape, or awave washer shape. In some embodiments, the friction element 3208 isadhered to the barrel cam cylinder 3220.

Interaction of the friction element 3208 with the follower guide 3221,and the resulting motion of the follower guide 3221 relative to thebarrel cam cylinder 3220, are described with reference to the cam slotand aperture profiles illustrated in FIGS. 22A-22C. Referring first toFIG. 22A and upon a first actuation of the trigger assembly, the triggerpin initially moves from position BC1′ to BC3′. As the trigger pin movesin this manner, the follower guide 3221 rotates together with the barrelcam cylinder 3220 due to the frictional forces between the frictionelement 3208 and the follower guide 3221. Stated another way, thefriction element 3208 initially holds the follower guide 3221 in thefirst locked position relative to the barrel cam cylinder 3220.

Referring to FIG. 22B and by continuing the first actuation of thetrigger assembly, the trigger pin moves from position BC3′ to BC4′. Inposition BC3′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC4′, the trigger pin applies aforce to the follower guide 3221 that overcomes the frictional forcesbetween the friction element 3208 and the follower guide 3221. As aresult, the friction element 3208 slips against the follower guide 3221,and the follower guide 3221 is “unlocked” and rotates relative to thebarrel cam cylinder 3220 as the trigger pin moves from position BC3′ toBC4′. When the trigger pin reaches position BC4′, the trigger pin nolonger applies the force to the follower guide 3221.

When the user releases the trigger assembly, the trigger pin moves fromposition BC4′ to BC6′. As the trigger pin moves in this manner, thefollower guide 3221 rotates together with the barrel cam cylinder 3220due to the frictional forces between the friction element 3208 and thefollower guide 3221. Stated another way, the friction element 3208 holdsthe follower guide 3221 in the second locked position relative to thebarrel cam cylinder 3220 after the first actuation of the triggerassembly.

Still referring to FIG. 22B and upon a second actuation of the triggerassembly, the trigger pin initially moves from position BC6′ to BC8′. Asthe trigger pin moves in this manner, the follower guide 3221 rotatestogether with the barrel cam cylinder 3220 due to the frictional forcesbetween the friction element 3208 and the follower guide 3221. Statedanother way, the friction element 3208 initially holds the followerguide 3221 in the second locked position relative to the barrel camcylinder 3220.

Referring to FIG. 22C and by continuing the second actuation of thetrigger assembly, the trigger pin moves from position BC8′ to BC9′. Inposition BC8′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC9′, the trigger pin applies aforce to the follower guide 3221 that overcomes the frictional forcesbetween the friction element 3208 and the follower guide 3221. As aresult, the friction element 3208 slips against the follower guide 3221,and the follower guide 3221 is “unlocked” and rotates relative to thebarrel cam cylinder 3220 as the trigger pin moves from position BC8′ toBC9′. When the trigger pin reaches position BC9′, the trigger pin nolonger applies the force to the follower guide 3221.

When the user releases the trigger assembly, the trigger pin moves fromposition BC9′ to BC1′. As the trigger pin moves in this manner, thefollower guide 3221 rotates together with the barrel cam cylinder 3220due to the frictional forces between the friction element 3208 and thefollower guide 3221. Stated another way, the friction element 3208 holdsthe follower guide 3221 in the first locked position relative to thebarrel cam cylinder 3220 after the second actuation of the triggerassembly.

In some embodiments, the barrel cam cylinder 3220 fixedly carriesmultiple friction elements. In some embodiments, the follower guide 3221fixedly carries one or more friction elements that engage the outersurface of the barrel cam cylinder 3220.

Referring now to FIGS. 33 and 34, an exemplary barrel cam assembly 3319is depicted. The barrel cam assembly 3319 may be used with a surgicaldevice, such as the surgical device 1206 described above, in place ofthe barrel cam assembly 1519. The barrel cam assembly 3319 includes abarrel cam cylinder 3320 that rotatably carries a follower guide 3321.The barrel cam cylinder 3320 and the follower guide 3321 may have thesame features as any of the barrel cam cylinders and the followerguides, respectively, described herein (for example, the cam groove 1544and the follower aperture 1565, respectively), with the exception of therelative rotation-inhibiting mechanism.

The barrel cam assembly 3319 includes a relative rotation-inhibitingmechanism 3375 that inhibits some rotation of the follower guide 3321relative to the barrel cam cylinder 3320. Generally, the relativerotation-inhibiting mechanism 3375 permits the follower guide 3321 tomove from a first relative rotation-inhibiting position (referred to asthe “first locked position” for simplicity) to a second relativerotation-inhibiting position (referred to as the “first locked position”for simplicity) and vice versa. In the first locked position, themechanism 3375 initially inhibits the follower guide 3321 from rotatingin a first direction relative to the barrel cam cylinder 3320 (that is,toward the second locked position) and inhibits rotation of the followerguide 3321 in a second direction relative to the barrel cam cylinder3320. In the second locked position, the mechanism 3375 initiallyinhibits the follower guide 3321 from rotating in the second directionrelative to the barrel cam cylinder 3320 (that is, toward the firstlocked position) and inhibits rotation of the follower guide 3321 in thefirst direction relative to the barrel cam cylinder 3320.

The relative rotation-inhibiting mechanism 3375 includes alongitudinally extending tab 3377 formed near the proximal end of thefollower guide 3321. The tab 3377 engages a semi-annular flange 3379formed near the proximal end of the barrel cam cylinder 3320. As shownin FIGS. 33 and 34, the tab 3377 engages one side of the flange 3379 inthe first locked position to inhibit the follower guide 3321 fromrotating in a direction away from the second locked position. The tab3377 engages the other side of the flange 3379 in the second lockedposition to inhibit the follower guide 3321 from rotating in a directionaway from the first locked position.

The relative rotation-inhibiting mechanism 3375 also includes a firstmagnetic element 3308 that is fixedly carried by the barrel cam cylinder3320. The first magnetic element 3308 may be a magnet or may be formedfrom one or more ferromagnetic materials that are attracted to magnets(for example, steel). The relative rotation-inhibiting mechanism 3375further includes second and third magnetic elements 3310 and 3312 thatare fixedly carried by the follower guide 3321. The second and thirdmagnetic elements 3310 and 3312 may be magnets or may be formed from oneor more ferromagnetic materials that are attracted to magnets (forexample, steel) if the first magnet element 3308 is a magnet.

Interaction of the first magnetic element 3308 with the second and thirdmagnetic elements 3310 and 3312, and the resulting motion of thefollower guide 3321 relative to the barrel cam cylinder 3320, aredescribed with reference to the cam slot and aperture profilesillustrated in FIGS. 22A-22C. Referring first to FIG. 22A and upon afirst actuation of the trigger assembly, the trigger pin initially movesfrom position BC1′ to BC3′. As the trigger pin moves in this manner, thefollower guide 3321 rotates together with the barrel cam cylinder 3320due to the magnetic attraction forces between the first magnetic element3308 and the second magnetic element 3310. Stated another way, the firstmagnetic element 3308 and the second magnetic element 3310 initiallyhold the follower guide 3321 in the first locked position relative tothe barrel cam cylinder 3320.

Referring to FIG. 22B and by continuing the first actuation of thetrigger assembly, the trigger pin moves from position BC3′ to BC4′. Inposition BC3′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC4′, the trigger pin applies aforce to the follower guide 3321 that overcomes the magnetic attractionforces between the first magnetic element 3308 and the second magneticelement 3310. As a result, the first magnetic element 3308 and thesecond magnetic element 3310 move apart, and the follower guide 3321 is“unlocked” and rotates relative to the barrel cam cylinder 3320 as thetrigger pin moves from position BC3′ to BC4′. As the trigger pinapproaches position BC4′, the first magnetic element 3308 and the thirdmagnetic element 3312 are magnetically attracted to each other. Thefollower guide 3321 thereby enters the second locked position relativeto the barrel cam cylinder 3320.

When the user releases the trigger assembly, the trigger pin moves fromposition BC4′ to BC6′. As the trigger pin moves in this manner, thefollower guide 3321 rotates together with the barrel cam cylinder 3320due to the magnetic attraction forces between the first magnetic element3308 and the third magnetic element 3312. Stated another way, the firstmagnetic element 3308 and the third magnetic element 3312 hold thefollower guide 3321 in the second locked position relative to the barrelcam cylinder 3320 after the first actuation of the trigger assembly.

Still referring to FIG. 22B and upon a second actuation of the triggerassembly, the trigger pin initially moves from position BC6′ to BC8′. Asthe trigger pin moves in this manner, the follower guide 3321 rotatestogether with the barrel cam cylinder 3320 due to the magneticattraction forces between the first magnetic element 3308 and the thirdmagnetic element 3312. Stated another way, the first magnetic element3308 and the third magnetic element 3312 initially hold the followerguide 3321 in the second locked position relative to the barrel camcylinder 3320.

Referring to FIG. 22C and by continuing the second actuation of thetrigger assembly, the trigger pin moves from position BC8′ to BC9′. Inposition BC8′, the trigger pin engages the wall of the follower guideaperture. By moving toward position BC9′, the trigger pin applies aforce to the follower guide 3321 that overcomes the magnetic attractionforces between the first magnetic element 3308 and the third magneticelement 3312. As a result, the first magnetic element 3308 and the thirdmagnetic element 3312 move apart, and the follower guide 3321 is“unlocked” and rotates relative to the barrel cam cylinder 3320 as thetrigger pin moves from position BC8′ to BC9′. As the trigger pinapproaches position BC9′, the first magnetic element 3308 and the secondmagnetic element 3310 are magnetically attracted to each other. Thefollower guide 3321 thereby returns to the first locked positionrelative to the barrel cam cylinder 3320.

When the user releases the trigger assembly, the trigger pin moves fromposition BC9′ to BC1′. As the trigger pin moves in this manner, thefollower guide 3321 rotates together with the barrel cam cylinder 3320due to the magnetic attraction forces between the first magnetic element3308 and the second magnetic element 3310. Stated another way, the firstmagnetic element 3308 and the second magnetic element 3310 hold thefollower guide 3321 in the first locked position relative to the barrelcam cylinder 3320 after the second actuation of the trigger assembly.

In some embodiments, the follower guide 3321 carries one magneticelement, and the barrel cam cylinder 3320 carries two magnetic elements.

FIG. 35 depicts two-dimensional illustrations of the profile of acutting tip slot 3516, the profile of a barrel cam slot 3544, and theprofile of a follower guide aperture 3565 that may be formed on any ofthe cutting tips, barrel cam cylinders, and follower guides,respectively, described herein. FIGS. 36A-36C depict the how actuationof a trigger (which may be any of the triggers described herein), andthe resulting movement of the trigger pin 3528 (which may be any of thetrigger pins described herein), results in rotational movement of thebarrel cam cylinder, the follower guide, and the cutting tip, andtranslation movement of the cutting tip. In these figures, a horizontalaxis for the profiles of the slots 3516 and 3544 is the degree(s) ofrotation of the cutting tip and the barrel cam cylinder. A vertical axisfor the profile of the cam slot 3516 for the cutting tip is the amountof longitudinal displacement, if any, of the cutting tip. The verticalaxis for the profile of the cam slot 3544 for the barrel cam cylinder isthe amount of longitudinal displacement of the trigger assembly (andtrigger pin).

In FIGS. 35A-35C, the aperture 3565 of the follower guide is shown as adashed line and is overlaid on the profile of the cam slot 3544 for thebarrel cam cylinder to illustrate the rotational position of theaperture 3565 relative to the cam slot 3544. As shown in FIGS. 35A-35Cand explained in further detail below, the rotational position of theaperture 3565 changes relative to the cam slot 3544 during actuation ofthe trigger.

Generally, an initial, or first, actuation of the trigger (that is,pulling the trigger as far as permitted by the handle assembly and thenreleasing the trigger so that it returns to its home position) resultsin a net rotational displacement of the cutting tip and the barrel camcylinder about 254 degrees in one direction—clockwise when looking fromthe handle to the tip. The first actuation also extends the cutting tipfrom the outer band and then returns the cutting tip to the sheathedposition as the cutting tip rotates. A subsequent, or second, actuationof the trigger results in a net rotational displacement of the cuttingtip and the barrel cam cylinder about 254 degrees in the oppositedirection—counter-clockwise when looking from the handle to the tip. Thesecond actuation also extends the cutting tip from the outer band andthen returns the cutting tip to the sheathed position as the cutting tiprotates. Additional “odd” actuations (that is, a third actuation, afifth actuation, and so on) cause the same device motions as the firstactuation of the trigger. Additional “even” actuations (that is, afourth actuation, a sixth actuation, and so on) cause the same devicemotions as the second actuation of the trigger.

Referring specifically to FIG. 36A, prior to the first actuation of thetrigger, the trigger pin is at a first home position (BC1″) within thebarrel cam cylinder, the guide pin is at its initial position (CT1″),and the cutting tip is at a recessed position within the outer sheath.In addition, the follower guide is at its first relativerotation-inhibiting position (GS1″) with respect to the barrel camcylinder. Upon initiating the first actuation of the trigger, thetrigger pin moves proximally, and the barrel cam cylinder, the cuttingtip, and the follower guide rotate in a clockwise direction relative tothe trigger pin (from a vantage point proximal of the barrel camcylinder). When the trigger pin is at position BC2″, the trigger pin isin the intersection 3545 of the barrel cam slot 3544. Additionally, whenthe trigger pin is at position BC2″ (i) the barrel cam cylinder andcutting tip have rotated about 127 degrees in a clockwise directionsince initiating the first actuation of the trigger, (ii) the guide pinis at position CT2″, and (iii) the cutting tip is at a partiallyextended position.

Continuing to refer to FIG. 36A, when the trigger pin is at positionBC2″, the trigger pin abuts a first curved wall 3567 of the followerguide aperture 3565. Because the first curved wall 3567 of the followerguide aperture 3565 is aligned with one path of the intersection 3545 ofthe barrel cam slot 3544, the follower guide prevents the trigger pinfrom traveling in the alternative path and guides the trigger pinstraight through the intersection 3545 of the barrel cam slot 3544 asthe trigger pin passes position BC2″. In some embodiments, the apexbetween the first curved wall 3567 and the second curved wall 3569 isoffset from the wall of the barrel cam slot 3544 in a longitudinaldirection (for example, by about 0.025 inches) to inhibit the triggerpin from engaging the apex. This facilitates guiding the trigger pinstraight through the intersection 3545 of the barrel cam slot 3544. Insome embodiments, the first curved wall 3567 extends beyond the wall ofthe barrel cam slot 3544 (for example, the perpendicular distancebetween the barrel cam slot 3544 and the furthest point on the firstcurved wall 3567 may be about 0.010 inches) to facilitate smooth motionof the trigger pin as the trigger pin passes through the intersection3545 and to permit a relatively small amount of misalignment between thebarrel cam and the follower guide.

As the user continues to pull the trigger, and the trigger pin continuesto move proximally, the barrel cam cylinder, the cutting tip, and thefollower guide continue to rotate in a clockwise direction from positionBC2″ to position BC3″. When the trigger pin is at position BC3″, (i) thebarrel cam cylinder and cutting tip have rotated about 140 degrees in aclockwise direction since initiating the first actuation of the trigger,(ii) the guide pin is at position CT3″, and (iii) the cutting tip is ata fully extended position.

As the user continues to pull the trigger, and the trigger pin continuesto move proximally, and the barrel cam cylinder, the cutting tip, andthe follower guide continue to rotate in a clockwise direction.Specifically, the trigger pin moves from position BC3″ to position BC4″.When the trigger pin is at position BC4″, (i) the barrel cam cylinderand cutting tip have rotated about 177 degrees in a clockwise directionsince initiating the first actuation of the trigger, (ii) the guide pinis at position CT4″, and (iii) the cutting tip is at a partiallyextended position.

When the trigger pin is at position BC4″, the trigger pin abuts a wall3571 of the follower guide aperture 3565. As the trigger pin has movedfrom the first home position (BC1″) to position BC4″, the follower guideand barrel cam cylinder have rotated in unison with one another due tothe presence of one of the relative rotation-inhibiting mechanismsdescribed above. For example, the barrel cam cylinder and the followerguide include the relative rotation-inhibiting mechanism 2475 (see FIGS.24-28). In this case, the first spring prong 2410 on the follower guidehas been engaged with the curved recess 2404 of the protrusion 2402 ofthe barrel cam cylinder, thereby preventing the follower guide andbarrel cam cylinder from rotationally moving relative to one another.Referring to FIG. 36B, as the trigger pin moves beyond position BC4″towards position BC5″, the trigger pin engages the wall 3571 of thefollower guide, thereby rotating the follower guide in acounter-clockwise direction relative to the barrel cam cylinder andforcing the follower guide from its first relative rotation-inhibitingposition (GS1″) to a movable position. That is, as the trigger pin movesfrom position BC4″ to position BC5″, the follower guide is in a movableposition relative to the barrel cam cylinder. Once the trigger pinreaches position BC5″, the follower guide and barrel cam cylinder are ina second relative rotation-inhibiting position (GS2″). In the secondrelative rotation-inhibiting position (GS2″), for example, the secondspring prong 2412 on the follower guide engages the curved recess 2404of the protrusion 2402 of the barrel cam cylinder, and a firstengagement surface 2413 on the follower guide engages the protrusion2402 to prevent the follower guide from further rotating in thecounter-clockwise direction relative to the barrel cam cylinder.

Continuing to refer to FIG. 36B, as the user continues to pull thetrigger to move the trigger pin from position BC4″ to position BC5″, thebarrel cam cylinder and the cutting tip continue to rotate in aclockwise direction relative to the trigger pin. The follower guide,however, does not continue to rotate relative to the trigger pin andthereby rotates relative to the barrel cam cylinder. Specifically, thefollower guide rotates about 110 degrees in a counter-clockwisedirection to a second relative rotation-inhibiting position (GS2″)relative to the barrel cam cylinder. When the trigger pin is at positionBC5″ (i) the trigger has reached the end of its proximal travel, (ii)the barrel cam cylinder has rotated about 287 degrees in a clockwisedirection since initiating the first actuation of the trigger, (iii) theguide pin is at position CT5″, and (iv) the cutting tip is at its mostrecessed position. In addition, the cutting tip has rotated a total ofabout 284 degrees in a clockwise direction since initiating the firstactuation of the trigger. The cutting tip rotates less than the barrelcam cylinder because the guide pin engages the wall of the cutting tipslot 3516 (that is, the guide pin reaches position CT5″) before thetrigger pin reaches position BC5″. The barrel cam cylinder rotates about3 degrees in the clockwise direction after the guide pin engages thewall of the cutting tip slot 3516. As a result, the barrel cam cylinderrotates about 3 degrees relative to the cutting tip when the trigger pinapproaches position BC5″. The relative rotation between the barrel camcylinder and the cutting tip is accounted for by rotational deflectionof the flexible inner sheath.

After the trigger pin reaches position BC5″, the user can release thetrigger. Upon the user releasing the trigger, the trigger and triggerpin reverse direction and travel toward their distal position due to theconstant force spring attached to the trigger. As the trigger andtrigger pin begin to move toward their distal position, the barrel camcylinder and cutting tip are rotationally stationary relative to thetrigger pin. Accordingly, upon the user releasing the trigger, thetrigger pin moves from position BC5″ toward position BC6″. When thetrigger is at position BC6″ (i) the barrel cam cylinder has rotatedabout 287 degrees in a clockwise direction since initiating the firstactuation of the trigger (ii) the guide pin is still at position CT5″,and (iii) the cutting tip is still at its most recessed position. Atposition BC6″, however, the trigger pin is still not at its most distalposition. To reach the trigger pin's most distal position BC7″, thebarrel cam cylinder rotates about 33 degrees in a counter-clockwisedirection. In some embodiments, the trigger pin engages a radiusedcorner of the wall of the barrel cam slot 3544 and/or the wall of thefollower guide aperture 3565 (for example, a 0.050 inch radius) whenmoving from position BC6″ to position BC7″. Such a structure mayfacilitate reliably sliding the trigger pin to position BC7″. When thetrigger pin is at position BC7″, the trigger pin is at a second homeposition within the barrel cam cylinder. When the trigger pin is atposition BC7″, (i) the barrel cam cylinder and the cutting tip haverotated a total of about 254 degrees in a clockwise direction sinceinitiating the first actuation of the trigger, (ii) the guide pin is atposition CT7″, and (iii) the cutting tip is recessed within the outersheath.

Still referring to FIG. 36B, when the trigger pin is at its second homeposition (BC7″), the follower guide is at its second relativerotation-inhibiting position (GS2″). Upon initiating a second actuationof the trigger to move the trigger pin proximally, the follower guideand the barrel cam cylinder remain stationary with respect to oneanother, and the barrel cam cylinder, the cutting tip, and the followerguide rotate in a counter-clockwise direction. When the trigger pin isat position BC8″, (i) the barrel cam cylinder and cutting tip haverotated about 114 degrees in a counter-clockwise direction sinceinitiating the second actuation of the trigger, (ii) the guide pin is atposition CT8″, and (iii) the cutting tip is at its most extendedposition.

As the user continues the second actuation of the trigger, and thetrigger pin continues to move proximally, the barrel cam cylinder, thecutting tip, and the follower guide continue to rotate in acounter-clockwise direction relative to the trigger pin. When thetrigger pin is at position BC9″, (i) the barrel cam cylinder and cuttingtip have rotated about 127 degrees in a counter-clockwise directionsince initiating the second actuation of the trigger, (ii) the guide pinis at position CT9″, (iii) the cutting tip is at a partially extendedposition, and (iv) the trigger pin is at the intersection 3545 of thebarrel cam slot 3544. When the trigger pin is at position BC9″, thetrigger pin abuts a second curved wall 3569 of the follower guideaperture 3565. Because the second curved wall 3569 of the follower guideaperture 3565 is aligned with one path of the intersection 3545 of thebarrel cam slot 3544, the follower guide prevents the trigger pin fromtraveling in the alternative path and guides the trigger pin straightthrough the intersection 3545 of the barrel cam slot 3544 as the triggerpin passes position BC9″.

As the user continues to actuate the trigger, and the trigger pincontinues to move proximally, the barrel cam cylinder, the cutting tip,and the follower guide continue to rotate in a counter-clockwisedirection. When the trigger pin is at position BC10″, (i) the barrel camcylinder and cutting tip have rotated about 177 degrees in a clockwisedirection since initiating the second actuation of the trigger, (ii) theguide pin is at position CT10″, (iii) the cutting tip is at a partiallyextended position, and (iv) the trigger pin abuts a wall 3573 of thefollower guide aperture 3565.

As the trigger pin has moved from its second home position (BC7″) toposition BC10″, the follower guide and barrel cam cylinder have rotatedin unison with one another due to the presence of the relativerotation-inhibiting mechanism. For example, the second spring prong 2412on the follower guide has been engaged with the curved recess 2404 ofthe protrusion 2402 of the barrel cam cylinder, thereby preventing thefollower guide and barrel cam cylinder from rotationally moving relativeto one another. Referring to FIG. 36C, as the trigger pin moves beyondposition BC10″ towards position BC11″, the trigger pin engages the wall3573 of the follower guide, thereby rotating the follower guide in theclockwise direction relative to the barrel cam cylinder and forcing thefollower guide from its second relative rotation-inhibiting position(GS2″) to a movable position. That is, as the trigger pin moves fromposition BC10″ to position BC11″, the follower guide is in a movableposition relative to the barrel cam cylinder. Once the trigger pinreaches position BC11″, the follower guide and barrel cam cylinder havereturned to the first relative rotation-inhibiting position (GS1″). Inthe first relative rotation-inhibiting position (GS1″), for example, thefirst spring prong 2410 on the follower guide engages the curved recess2404 of the protrusion 2402 of the barrel cam cylinder, and a secondengagement surface 2414 on the follower guide (see FIG. 25) engages theprotrusion 2402 to prevent the follower guide from further rotating inthe clockwise direction relative to the barrel cam cylinder.

Continuing to refer to FIG. 36C, as the user continues the secondactuation of the trigger, and the trigger pin continues to moveproximally, the barrel cam cylinder and the cutting tip continue torotate in a counter-clockwise direction. The follower guide, however,does not continue to rotate relative to the trigger pin, and the triggerpin rotates only relative to the barrel cam cylinder. Specifically, thefollower guide rotates about 110 degrees in a clockwise direction to thefirst relative rotation-inhibiting position (GS1″) relative to thebarrel cam cylinder. When the trigger pin is at position BC11″ (i) thetrigger has reached the end of its proximal travel, (ii) the barrel camcylinder and the cutting tip have rotated about 287 degrees in acounter-clockwise direction since initiating the second actuation of thetrigger, (iii) the guide pin is at position CT11″, and (iv) the cuttingtip is at its most recessed position.

After the trigger pin reaches position BC11″, the user can release thetrigger. Upon the user releasing the trigger, the trigger and triggerpin reverse direction and travel toward their distal position due to theconstant force spring attached to the trigger. As the trigger andtrigger pin begin to move toward their distal position, the barrel camcylinder and cutting tip are rotationally stationary relative to thetrigger pin. Accordingly, upon the user releasing the trigger, thetrigger pin moves from position BC11″ toward position BC12″. When thetrigger is at position BC12″ (i) the barrel cam cylinder and the cuttingtip are still rotated about 287 degrees in a counter-clockwise directionsince initiating the second actuation of the trigger (ii) the guide pinis still at position CT11″, and (iii) the cutting tip is still at itsmost recessed position. As the trigger and trigger pin continue to movetoward their distal position, the barrel cam cylinder and cutting tiprotate about 33 degrees in a clockwise direction relative to the triggerpin and the trigger pin returns to its first home position (BC1″). Insome embodiments, the trigger pin engages a radiused corner of the wallof the barrel cam slot 3544 and/or the wall of the follower guideaperture 3565 (for example, a 0.050 inch radius) when moving fromposition BC12″ to position BC1″. Such a structure may facilitatereliably sliding the trigger pin to position BC1″. When the trigger pinreturns to its first home position (BC1″), the guide pin returns to itsinitial position (CT1″), and the cutting tip remains at a recessedposition within the outer sheath. The user may then repeat the process,if so desired.

FIG. 37 depicts a two-dimensional illustration of the profile of abarrel cam slot 3744 that may be formed on any of the barrel camcylinders described herein. The cam slot 3744 defines a generally“hourglass”-like or “figure eight”-like path for the follower (forexample, the trigger pin 1528). The trigger pin traverses about half ofthe cam slot 3744 when an initial, or first, actuation is applied to thetrigger, and the trigger pin traverses the remainder of the cam slot3744 (that is, about half of the cam slot 3744) when a subsequent, orsecond, actuation is applied to the trigger. In each case, the followerguide (for example, the follower guide 1521) causes the trigger pin totravel straight through the intersection (or crossing portion) 3745 ofthe cam slot 3744 during each actuation of the trigger. Stated anotherway, the follower guide causes the trigger pin to travel from a firstleg 3747 of the cam slot 3744 to a second leg 3749 of the cam slot 3744,and then from a third leg 3751 of the cam slot 3744 to a fourth leg 3753of the cam slot 3744.

Each of the legs 3747, 3749, 3751, and 3753 is shaped to inhibit thetrigger pin from engaging the walls of the legs 3747, 3749, 3751, and3753 when travelling through the intersection 3745 and potentiallybinding up with the barrel cam assembly. In some embodiments, each ofthe legs 3747, 3749, 3751, and 3753 has a width that taperinglyincreases proceeding toward the intersection 3745. Specifically, thefirst leg 3747 includes a first angled wall 3760 that is adjacent to theintersection 3745 and disposed on a distal side of the first leg 3747.The first angled wall 3760 is angled away from the first trigger pinpath 3762 (that is, the path traversed by the trigger pin during thefirst actuation of the trigger) proceeding toward the intersection 3745.The first angled wall 3760 may have a length in the range of about 0.25to 0.40 inches, and more specifically about 0.33 inches, and may beangled away from the first trigger pin path 3762 by an angle in therange of about 1 to 7 degrees, and more specifically about 4 degrees.Similarly, the second leg 3749 includes a second angled wall 3764 thatis adjacent to the intersection 3745 and disposed on a distal side ofthe second leg 3749. The second angled wall 3764 is angled away from thefirst trigger pin path 3762 proceeding toward the intersection 3745. Thesecond angled wall 3764 may have a length in the range of about 0.18 to0.32 inches, and more specifically about 0.25 inches, and may be angledaway from the first trigger pin path 3762 by an angle in the range ofabout 4 to 10 degrees, and more specifically about 7 degrees. The thirdleg 3751 includes a third angled wall 3766 that is adjacent to theintersection 3745 and disposed on a distal side of the third leg 3751.The third angled wall 3766 is angled away from the second trigger pinpath 3768 (that is, the path traversed by the trigger pin during thesecond actuation of the trigger) proceeding toward the intersection3745. The third angled wall 3766 may have a length in the range of about0.25 to 0.40 inches, and more specifically about 0.33 inches, and may beangled away from the second trigger pin path 3768 by an angle in therange of about 1 to 7 degrees, and more specifically about 4 degrees.The fourth leg 3753 includes a fourth angled wall 3770 that is adjacentto the intersection 3745 and disposed on a distal side of the fourth leg3753. The fourth angled wall 3770 is angled away from the second triggerpin path 3768 proceeding toward the intersection 3745. The fourth angledwall 3770 may have a length in the range of about 0.18 to 0.32 inches,and more specifically about 0.25 inches, and may be angled away from thesecond trigger pin path 3768 by an angle in the range of about 4 to 10degrees, and more specifically about 7 degrees.

The discussion above describes a barrel cam cylinder and a followerguide in the context of a medical device. However, barrel cam cylindersand follower guides according to the disclosure may be used with othertypes of devices (for example, non-medical devices) to convert atranslational input to a rotational output. That is, barrel camcylinders and follower guides according to the disclosure may be usedsuch that a first translational input (for example, a first actuation ofa translatable trigger) causes a first rotational output (for example,rotation of a shaft in a first direction) and a second translationalinput (for example, a second actuation of the translatable trigger)causes a second rotational output (for example, rotation of the shaft ina second direction).

The discussion above discusses that the inner sheath, including thecutting tip, travel at certain rates (e.g., constant and/or variable).However, the rates are also dependent upon the speed at which the innersheath rotates and travels longitudinally (i.e., extends and/orretracts), and in turn, upon the speed of the actuation of the triggerassembly, including the longitudinal movement of the trigger and therotational movement of the barrel cam cylinder. Accordingly, thediscussion and/or comparison of the rates at which the blade travelsassumes that the means for actuating extends the inner sheath at arelatively constant speed. Regardless of whether this assumption iscorrect, the greater the amount of blade extension per predeterminedamount of rotation, the blade will extend at a greater rate and speed,thereby providing the surgical device with the ability to cut moretissue per rotation.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a letter thatdistinguishes among the similar components. If only the first referencelabel is used in the specification, the description is applicable to anyone of the similar components having the same first reference labelirrespective of the second reference label.

A number of variations and modifications of the disclosure may be used.It would be possible to provide for some features of the disclosurewithout providing others.

In some embodiments, the systems and methods of this disclosure may beimplemented in conjunction with a special purpose computer, a programmedmicroprocessor or microcontroller and peripheral integrated circuitelement(s), an ASIC or other integrated circuit, a digital signalprocessor, a hard-wired electronic or logic circuit such as discreteelement circuit, a programmable logic device or gate array such as PLD,PLA, FPGA, PAL, special purpose computer, any comparable means, or thelike. In general, any device(s) or means capable of implementing themethodology illustrated herein may be used to implement the variousaspects of this disclosure. Exemplary hardware that may be used for thedisclosed embodiments, configurations and aspects includes computers,handheld devices, telephones (e.g., cellular, Internet enabled, digital,analog, hybrids, and others), and other hardware known in the art. Someof these devices include processors (e.g., a single or multiplemicroprocessors), memory, nonvolatile storage, input devices, and outputdevices. Furthermore, alternative software implementations including,but not limited to, distributed processing or component/objectdistributed processing, parallel processing, or virtual machineprocessing may also be constructed to implement the methods describedherein.

The present disclosure, in various aspects, embodiments, and/orconfigurations, includes components, methods, processes, systems and/orapparatus substantially as depicted and described herein, includingvarious aspects, embodiments, configurations embodiments, subcombinations, and/or subsets thereof. Those of skill in the art willunderstand how to make and use the disclosed aspects, embodiments,and/or configurations after understanding the present disclosure. Thepresent disclosure, in various aspects, embodiments, and/orconfigurations, includes providing devices and processes in the absenceof items not depicted and/or described herein or in various aspects,embodiments, and/or configurations hereof, including in the absence ofsuch items as may have been used in previous devices or processes, e.g.,for improving performance, achieving ease and/or reducing cost ofimplementation.

For example, although a pin and slot cam configuration is discussedwithin this disclosure, other possible cam configurations may be used.For example, a captured ring cam configuration may be used. A capturedring cam configuration may include a ring that is attached to at leastone of the inner sheath (or inner member attached to the inner sheath)or the outer sheath (or outer member attached to the outer sheath) andthat is captured by two angled lobes on the other sheath (or member).Although the ring may be captured by one lobe, it may be preferred forthe ring to be captured by two lobes—one on each side of the ring—suchthat cutting surface may be forced in both a proximal direction (towarda retraction position) and distal direction (toward an extendeddirection). The benefit of being able to force the cutting surface inboth directions with the aid of the captured cam configurationpotentially negates the need for a spring or other refraction mechanismto force the inner sheath (or inner member) and cutting surface backwithin the outer sheath (or outer member.

Another example of an alternate embodiment may include replacing thecutting tip with a dilator top or separator tip. A further example of analternate embodiment may include varying the degrees of rotation of theinner sheath assembly or the barrel cam cylinder in the clockwise and/orcounter-clockwise direction. An even further example of an alternateembodiment may include the barrel cam cylinder and the inner sheathassembly first rotating in a counter-clockwise direction followed byrotating in a clockwise direction.

The foregoing discussion has been presented for purposes of illustrationand description. The foregoing is not intended to limit the disclosureto the form or forms disclosed herein. In the foregoing Summary forexample, various features of the disclosure are grouped together in oneor more aspects, embodiments, and/or configurations for the purpose ofstreamlining the disclosure. The features of the aspects, embodiments,and/or configurations of the disclosure may be combined in alternateaspects, embodiments, and/or configurations other than those discussedabove. This method of disclosure is not to be interpreted as reflectingan intention that the claims require more features than are expresslyrecited in each claim. Rather, as the following claims reflect,inventive aspects lie in less than all features of a single foregoingdisclosed aspect, embodiment, and/or configuration. Thus, the followingclaims are hereby incorporated into this Summary, with each claimstanding on its own as a separate preferred embodiment of thedisclosure.

Moreover, though the description has included description of one or moreaspects, embodiments, and/or configurations and certain variations andmodifications, other variations, combinations, and modifications arewithin the scope of the disclosure, e.g., as may be within the skill andknowledge of those in the art, after understanding the presentdisclosure. It is intended to obtain rights which include alternativeaspects, embodiments, and/or configurations to the extent permitted,including alternate, interchangeable and/or equivalent structures,functions, ranges or steps to those claimed, whether or not suchalternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

What is claimed is:
 1. A device for removing an implanted object from abody vessel, the device comprising: a sheath assembly comprising anouter sheath assembly and an inner sheath assembly, and a pin; the outersheath assembly comprising an outer sheath and an outer band, the outerband coupled to the pin; the inner sheath assembly comprising an innersheath and a tip, wherein the tip has a cutting surface; the innersheath comprising a proximal end and a distal end, wherein the distalend of the inner sheath is coupled to the tip; the tip comprising a camslot for receipt of and cooperation with the pin; and a handle assemblycomprising a trigger and a barrel cam cylinder, the trigger comprising atrigger pin, the barrel cam cylinder comprising a barrel cam cylinderslot for receipt and cooperation with the trigger pin, wherein theproximal end of the inner sheath is coupled to the barrel cam cylindersuch that: (1) upon a first actuation of the trigger to proximally movethe trigger pin in a longitudinal direction, the barrel cam cylinderrotates in a first direction, thereby causing the tip to rotate in thefirst direction while the tip moves longitudinally; and (2) upon asecond actuation of the trigger to proximally move the trigger pin inthe longitudinal direction, the barrel cam cylinder rotates in a seconddirection, thereby causing the tip to rotate in the second directionwhile the tip moves longitudinally; wherein the barrel cam cylinder slotcomprises an intersection in which a path defined by the barrel camcylinder slot crosses itself, and the handle assembly further comprisesa follower guide rotatably carried by the barrel cam cylinder, thefollower guide engaging the trigger pin to guide the trigger pinstraight through intersection during both the first actuation of thetrigger and the second actuation of the trigger.
 2. The device of claim1, wherein the outer sheath assembly is stationary and the inner sheathassembly is capable of rotating.
 3. The device of claim 1, wherein thepin couples the tip of the inner sheath assembly to the outer band ofthe outer sheath assembly.
 4. The device of claim 1, wherein the handleassembly further comprises a spring assembly coupled to the trigger. 5.The device of claim 4, wherein the spring assembly is a constant forcespring.
 6. The device of claim 1, wherein the follower guide comprises:a first wall that engages the trigger pin to guide the trigger pinstraight through intersection during the first actuation of the trigger;and a second wall that engages the trigger pin to guide the trigger pinstraight through intersection during the second actuation of thetrigger.
 7. The device of claim 6, wherein the first wall is a firstdiagonally-extending wall and the second wall is a seconddiagonally-extending wall.
 8. The device of claim 7, wherein the firstdiagonally-extending wall is a first curved wall and the seconddiagonally-extending wall is a second curved wall.
 9. The device ofclaim 1, wherein the tip extends from and retracts into the outer bandwhile the barrel cam cylinder rotates in the first direction.
 10. Thedevice of claim 9, wherein the tip extends from and retracts into theouter band while the barrel cam cylinder rotates in the seconddirection.
 11. The device of claim 1, wherein the tip extends from andretracts into the outer band while the barrel cam cylinder rotates inthe second direction.
 12. A device for removing an implanted object froma body vessel, the device comprising: a sheath comprising a proximal endand a distal end; a tip coupled to the distal end of the sheath, whereinthe tip has a cutting surface; a handle assembly rotatably carrying thesheath, the handle assembly comprising: a trigger comprising a triggerpin; a barrel cam assembly comprising: a barrel cam cylinder comprisinga barrel cam cylinder slot for receipt and cooperation with the triggerpin, the barrel cam cylinder slot comprising a first slot portion and asecond slot portion; a follower guide rotatably carried by the barrelcam cylinder; wherein upon a first actuation of the trigger toproximally move the trigger pin in a longitudinal direction, thefollower guide urges the trigger pin to traverse the first slot portion,thereby causing the barrel cam cylinder and the tip to rotate in a firstdirection; and wherein upon a second actuation of the trigger toproximally move the trigger pin in the longitudinal direction, thefollower guide urges the trigger pin to traverse the second slotportion, thereby causing the barrel cam cylinder and the tip to rotatein a second direction.
 13. The device of claim 12, wherein the followerguide comprises an aperture through which the trigger pin extends forreceipt in and cooperation with the barrel cam cylinder slot.
 14. Thedevice of claim 13, wherein the follower guide further comprises: afirst wall that defines, in part, the aperture, the first wall engagingthe trigger pin to urge the trigger pin to traverse the first slotportion during the first actuation of the trigger; and a second wallthat defines, in part, the aperture, the second wall engaging thetrigger pin to urge the trigger pin to traverse the second slot portionduring the second actuation of the trigger.
 15. The device of claim 14,wherein the first wall is a first diagonally-extending wall and thesecond wall is a second diagonally-extending wall.
 16. The device ofclaim 12, wherein the barrel cam cylinder slot comprises an intersectionin which the first slot portion crosses the second slot portion, and thefollower guide (1) inhibits the trigger pin from traversing the secondslot portion during the first actuation of the trigger, and (2) inhibitsthe trigger pin from traversing the first slot portion during the secondactuation of the trigger.
 17. The device of claim 12, wherein thefollower guide is rotatable from a first position to a second positionand vice versa relative to the barrel cam cylinder, in the firstposition the follower guide urges the trigger pin to traverse the firstslot portion upon the first actuation of the trigger, thereby causingthe barrel cam cylinder and the tip to rotate in the first direction,and in the second position the follower guide urges the trigger pin totraverse the second slot portion upon the second actuation of thetrigger, thereby causing the barrel cam cylinder and the tip to rotatein the second direction.
 18. The device of claim 17, wherein the devicefurther includes a mechanism that inhibits the follower guide fromrotating relative to the barrel cam cylinder, the mechanism including: aprotrusion carried by the barrel cam cylinder; a first spring prongcarried by the follower guide, the first spring prong engaging theprotrusion in the first position to inhibit the follower guide fromrotating toward the second position; and a second spring prong carriedby the follower guide, the second spring prong engaging the protrusionin the second position to inhibit the follower guide from rotatingtoward the first position.
 19. The device of claim 18, wherein theprotrusion comprises a curved recess, the first spring prong includes afirst curved tip that engages the curved recess in the first position toinhibit the follower guide from rotating toward the second position, andthe second spring prong includes a second curved tip that engages thecurved recess in the second position to inhibit the follower guide fromrotating toward the first position.